defender2yara: Convert Microsoft Defender Antivirus Signatures (VDM) into YARA rules

defender2yara

defender2yara is a Python tool that converts Microsoft Defender Antivirus Signatures (VDM) into YARA rules. This tool facilitates the creation of custom YARA rules from the latest signature databases or manually provided .vdm files from Microsoft Defender, allowing for enhanced malware detection, analysis, and threat hunting.

This project focuses solely on antivirus signatures and does NOT address EDR signatures or detection logic.

Feature

• Convert Microsoft Defender Antivirus Signatures (VDM) to YARA rules.
  • Supports strings and hex bytes pattern matching with regex-like expression
  • Supports to convert scoring rules into YARA conditions
• Download the latest signature database.
• Export YARA rules into a single file or files per malware family.
• Add file-header checks to the rules to optimize the scan with the generated YARA rules.
• Manually specify the paths for base and delta VDM files.

• Some regex-like pattern matching in Microsoft Defender cannot be fully converted due to:
  • Limitations of the YARA engine
  • Undocumented or unknown implementations within mpengine.dll
• Several advanced features of Microsoft Defender are not supported, such as:
  • Emulator engines
  • Logic implemented in Lua
  • Unpacker modules
  • And other proprietary technologies