sheep-wolf – Exploit MD5 Collisions For Malware Detection


sheep-wolf is a tool to help you Exploit MD5 Collisions in software, specially malware samples which are commonly detected using MD5 hash signatures.

sheep-wolf - Exploit MD5 Collisions For Malware Detectionand then a malicious one (Wolf) that have the same MD5 hash. Please use this code to test if the security products in your reach use MD5 internally to fingerprint binaries and share your results by issuing a pull request updating the contents of results/!

Dependencies

  • 32-bit Windows (virtual) machine (64-bit breaks stuff)
  • Visual Studio 2012 to compile the projects (Express will do)
  • Fastcoll for collisions
  • Optional: Cygwin+MinGW to compile Evilize

How does it work?

  • shepherd.bat executes shepherd.exe with the user supplied command line arguments
    • shepher.exe generates a header file (sc.h) that contains the encrypted shellcode, the password and the CRC of the plain shellcode
  • shepherd.bat executes the build process of sheep.exe
    • sheep.exe is built with sc.hincluded by Visual Studio
  • shepherd.bat executes evilize.exe
    • evilize.exe calculates a special IV for the chunk of sheep.exe right before the block where the collision will happen
    • evilize.exe executes fastcoll.exe with the IV as a parameter
      • fastcoll.exe generates two 128 byte colliding blocks: a and b
    • evilize.exe replaces the original string buffers of sheep.exe so that they contain combinations a and b
    • The resulting files (evilize/wolf.exe and evilize/sheep.exe ) have the same MD5 hashes but behave differently. The real code to be executed only appears in the memory of evilize/wolf.exe.

You can download sheep-wolf here:

sheep-wolf-master.zip

Or read more here.

Posted in: Cryptography, Forensics, Malware

,


Latest Posts:


LambdaGuard - AWS Lambda Serverless Security Scanner LambdaGuard – AWS Lambda Serverless Security Scanner
LambdaGuard is a tool which allows you to visualise and audit the security of your serverless assets, an open-source AWS Lambda Serverless Security Scanner.
exe2powershell - Convert EXE to BAT Files exe2powershell – Convert EXE to BAT Files
exe2powershell is used to convert EXE to BAT files, the previously well known tool for this was exe2bat, this is a version for modern Windows.
HiddenWall - Create Hidden Kernel Modules HiddenWall – Create Hidden Kernel Modules
HiddenWall is a Linux kernel module generator used to create hidden kernel modules to protect your server from attackers.
Anteater - CI/CD Security Gate Check Framework Anteater – CI/CD Security Gate Check Framework
Anteater is a CI/CD Security Gate Check Framework to prevent the unwanted merging of filenames, binaries, deprecated functions, staging variables and more.
Stardox - Github Stargazers Information Gathering Tool Stardox – Github Stargazers Information Gathering Tool
Stardox is a Python-based GitHub stargazers information gathering tool, it scrapes Github for information and displays them in a list tree view.
ZigDiggity - ZigBee Hacking Toolkit ZigDiggity – ZigBee Hacking Toolkit
ZigDiggity a ZigBee Hacking Toolkit is a Python-based IoT (Internet of Things) penetration testing framework targeting the ZigBee smart home protocol.


Comments are closed.