Shhhloader is a work in progress shellcode loader. It takes raw shellcode as input and compiles a C++ stub that does a bunch of different things to try and bypass AV/EDR. The included python builder will work on any Linux system that has Mingw-w64 installed.
12/6/23 EDIT: Havoc C2 support has been added via a module by @jakobfriedl! Also, the default sandbox evasion method has been updated for better results. ;) See below for a video demonstrating the new module:
See Video
Shhhavoc_Demo.mp4
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┻┳| •.•) - Shhhhh, AV might hear us!
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usage: Shhhloader.py [-h] [-p explorer.exe] [-m QueueUserAPC] [-u] [-w] [-nr] [-ns] [-l] [-v] [-sc GetSyscallStub] [-d] [-dp apphelp.dll] [-s domain]
[-sa testlab.local] [-o a.exe] [-pp explorer.exe] [-ppv] [-np] [-cp] [-td ntdll.dll] [-ef NtClose]
file
ICYGUIDER'S CUSTOM SYSCALL SHELLCODE LOADER
positional arguments:
file File containing raw shellcode
options:
-h, --help show this help message and exit
-p explorer.exe, --process explorer.exe
Process to inject into (Default: explorer.exe)
-m QueueUserAPC, --method QueueUserAPC
Method for shellcode execution (Options: ThreadlessInject, ModuleStomping, QueueUserAPC, ProcessHollow, EnumDisplayMonitors,
RemoteThreadContext, RemoteThreadSuspended, CurrentThread) (Default: QueueUserAPC)
-u, --unhook Unhook NTDLL in current process
-w, --word-encode Save shellcode in stub as array of English words
-nr, --no-randomize Disable syscall name randomization
-ns, --no-sandbox Disable sandbox checks
-l, --llvm-obfuscator
Use Obfuscator-LLVM to compile stub
-v, --verbose Enable debugging messages upon execution
-sc GetSyscallStub, --syscall GetSyscallStub
Syscall execution method (Options: SysWhispers2, SysWhispers3, GetSyscallStub, None) (Default: GetSyscallStub)
-d, --dll Generate a DLL instead of EXE
-dp apphelp.dll, --dll-proxy apphelp.dll
Create Proxy DLL using supplied legitimate DLL (File must exist in current dir)
-s domain, --sandbox domain
Sandbox evasion technique (Options: sleep, domain, hostname, username, dll) (Default: sleep)
-sa testlab.local, --sandbox-arg testlab.local
Argument for sandbox evasion technique (Ex: WIN10CO-DESKTOP, testlab.local)
-o a.exe, --outfile a.exe
Name of compiled file
PPID Spoofing:
-pp explorer.exe, --ppid explorer.exe
Parent process to use for PPID Spoofing (Default: explorer.exe)
-ppv, --ppid-priv Enable spoofing for privileged parent process (Disabled by default)
-np, --no-ppid-spoof Disable PPID spoofing
ThreadlessInject:
-cp, --create-process
Create process instead of injecting into existing one
-td ntdll.dll, --target-dll ntdll.dll
Target DLL containing export function to overwrite
-ef NtClose, --export-function NtClose
Export function to overwrite
Features:
- 8 Different Shellcode Execution Methods (ThreadlessInject, ModuleStomping, QueueUserAPC, ProcessHollow, EnumDisplayMonitors, RemoteThreadContext, RemoteThreadSuspended, CurrentThread)
- PPID Spoofing
- Block 3rd Party DLLs
- Unhook NTDLL via KnownDLLs
- SysWhispers2, SysWhispers3, & GetSyscallStub
- API Hashing for SW2 & SW3
- Compile-Time String Encryption
- Obfuscator-LLVM (OLLVM) Support
- Automatic DLL Proxy Generation
- Syscall Name Randomization
- Store Shellcode as English Word Array
- XOR Encoding with Dynamic Key Generation
- Sandbox Evasion via Loaded DLL, Domain, User, Hostname, and System Enumeration
See below for a PoC video of the ThreadlessInject method being used to inject a Havoc beacon into IE without generating any alerts and minimal events in Microsoft Defender for Endpoint (MDE) EDR (Recorded 4/3/2023):
Shhhloader_ThreadlessInject_vs_Microsoft_Defender_for_Endpoint.mp4
See below video demonstrating the Module Stomping injection technique executed via DLL Proxying (Recorded 8/9/2022):
See Video
Shhhloader_Module_Stomping_DLL_Proxying.mp4
Shhhloader also contains an aggressor script for use with Cobalt Strike! Simply import the Shhhloader.cna file with the script manager to use. All files used/created by the aggressor script should be located in your locally cloned Shhhloader repo.
See Screenshot
Known Issues:
- The ThreadlessInject shellcode execution method must currently inject into a non-suspended process. This is done automatically for you if the "-cp" option is supplied. I hope to figure out a way to get it working with suspended processes soon.
- The Havoc C2 module currently hangs when specifying a Listener instead of a raw shellcode file. This will be fixed soon hopefully.
- The Cobalt Strike aggressor script has not been updated. It is probably broken unless used with older Shhhloader versions. It will be updated & fixed when I have time.
- Windows Defender will detect most files generated by this tool, so please do not post an issue saying "DETECTED!!!". Play around with the new options and features until you get something that works; they were added for a reason :). Executing the generated file in memory is also a good way to evade these detections.
- Obfuscator-LLVM (OLLVM) is not compatible with SW2 & SW3 due to how clang handles inline assembly. There is currently no plan to make them compatible; checks have been added to prevent the user from trying to use these features together.
- There are a ton of bugs in my code. Please test everything in advance before using for something important, and PLEASE provide as much information as possible when opening an issue. (THANKS!)
Planned Updates:
- Hardware Breakpoint (HWBP) syscall option
- Create processess using syscall instead of standard WinAPI function
- Integrate ThreadlessInject with other shellcode injection techniques (Ex. ModuleStomping)
- Refactor code to be more modular and readable
- Fix bugs in Havoc C2 module
- Fix countless bugs by learning to program better ;)
OPTIONAL: To use the Obfuscator-LLVM flag, you must have it installed on your system alongside wclang. I've found this to be a bit of a pain but you should be able to do it with a little perseverance. Here's a step-by-step that I used to install the llvm-13.x branch of OLLVM on my Kali Linux system:
See Details
# Clone and Run CMake
git clone -b llvm-13.x https://github.com/heroims/obfuscator.git
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_NEW_PASS_MANAGER=OFF ../obfuscator/llvm/
# Configure CMake and Compile OLLVM
export clang_build_dir=$(cd ../; pwd)/obfuscator/clang
sed -i 's/LLVM_TOOL_CLANG_BUILD:BOOL=OFF/LLVM_TOOL_CLANG_BUILD:BOOL=ON/g' CMakeCache.txt
sed -i "s|LLVM_EXTERNAL_CLANG_SOURCE_DIR:PATH=|LLVM_EXTERNAL_CLANG_SOURCE_DIR:PATH=$clang_build_dir|g" CMakeCache.txt
make -j7
# ONCE COMPILED, BACKUP ORIGINAL CLANG BINARIES
mv /usr/bin/clang /usr/bin/clang13.0.1
mv /usr/bin/clang++ /usr/bin/clang++13.0.1
# Then in OLLVM build/bin dir, copy the newly build clang bins
cp bin/clang /usr/bin/clang
cp bin/clang++ /usr/bin/clang++
# Then install wclang
cd ..
git clone https://github.com/tpoechtrager/wclang.git
cd wclang/
cmake -DCMAKE_INSTALL_PREFIX=_prefix_ .
make
make install
export wclang_path=$(pwd)/_prefix_/bin
echo "export PATH=$wclang_path:$PATH" >> ~/.bashrc
export PATH=$wclang_path:$PATH
# Then backup original lib files
cp -R /lib/llvm-13/lib/clang/13.0.1/include/ /lib/llvm-13/lib/clang/13.0.1/include_backup/
# Finally in the OLLVM build/bin/lib/clang/13.0.1/ dir, copy the include folder
cd ../build/lib/clang/13.0.1/
cp -R include/ /lib/llvm-13/lib/clang/13.0.1/
There is probably a better way to do this but this is what worked for me. If you have issues, just keep trying and ensure that you can run x86_64-w64-mingw32-clang++ -v and it contains either "Obfuscator-LLVM" or "heroims" in the output. Unfortunately I do not have the time to assist individuals who may need more help, but you can try reading this issue on my Nimcrypt2 repo where a couple of users figured out how to do it on their systems.
Greetz & Credit:
- @Jackson_T for his amazing project SysWhispers: https://github.com/jthuraisamy/SysWhispers
- @FalconForceTeam for their syscall generation tool that supports SysWhispers2: https://github.com/FalconForceTeam/SysWhispers2BOF
- @snovvcrash for their DInjector project, which I used as a template for many of the included injection techniques: https://github.com/snovvcrash/DInjector
- @Cerbersec for their Ares project, whose code I used for PPID Spoofing, Blocking 3rd Party DLLs and Sandbox Evasion: https://github.com/Cerbersec/Ares
- @spotheplanet for their blog post on Retrieving ntdll Syscall Stubs from Disk at Run-time: https://www.ired.team/offensive-security/defense-evasion/retrieving-ntdll-syscall-stubs-at-run-time
- @_RastaMouse for his code and article on Module Stomping which I ported to C++: https://offensivedefence.co.uk/posts/module-stomping/
- @s4ntiago_p for their NanoDump project and the randomize_sw2_seed.py script in particular: https://github.com/helpsystems/nanodump
- @skadro-official for their skCrypter project that this tool utilizes for compile-time string encryption: https://github.com/skadro-official/skCrypter
- @_EthicalChaos_ for their ThreadlessInject project: https://github.com/CCob/ThreadlessInject
- 0xLegacyy for their BOF version of ThreadlessInject: https://github.com/iilegacyyii/ThreadlessInject-BOF
- @D1rkMtr for their ntdll unhooking collection project: https://github.com/TheD1rkMtr/ntdlll-unhooking-collection
- @KlezVirus for their SysWhispers3 project: https://github.com/klezVirus/SysWhispers3
- @jakobfriedl for making a Havoc C2 Module for Shhhloader