check for hardware breakpoints

rule:
  meta:
    name: check for hardware breakpoints
    namespace: anti-analysis/anti-debugging/debugger-detection
    authors:
      - michael.hunhoff@mandiant.com
    scopes:
      static: function
      dynamic: unsupported  # requires offset, mnemonic features
    mbc:
      - Anti-Behavioral Analysis::Debugger Detection::Hardware Breakpoints [B0001.005]
    references:
      - https://github.com/LordNoteworthy/al-khaser/blob/master/al-khaser/AntiDebug/HardwareBreakpoints.cpp
    examples:
      - al-khaser_x86.exe_:0x42035D
  features:
    - and:
      - api: kernel32.GetThreadContext
      - number: 0x10010 = CONTEXT_DEBUG_REGISTERS
      - offset: 0x4 = DR0
      - offset: 0x8 = DR1
      - offset: 0xC = DR2
      - offset: 0x10 = DR3
      - count(mnemonic(cmp)): 4 or more