CobaltStrike_Resources_Beacon_Dll_v1_47

rule CobaltStrike_Resources_Beacon_Dll_v1_47
{
  meta:
    description = "Cobalt Strike's resources/beacon.dll Version 1.47"
    hash = "8ff6dc80581804391183303bb39fca2a5aba5fe13d81886ab21dbd183d536c8d"
		author = "gssincla@google.com"
		reference = "https://cloud.google.com/blog/products/identity-security/making-cobalt-strike-harder-for-threat-actors-to-abuse"
		date = "2022-11-18"

    id = "ac2249a9-210c-581f-8dd1-7619356dca7d"
  strings:
    /*
      83 F8 12  cmp     eax, 12h
      77 10     ja      short def_100010BB; jumptable 100010BB default case, case 8
      FF 24 ??  jmp     ds:jpt_100010BB[eax*4]; switch jump
    */
    $version_sig = { 83 F8 12 77 10 FF 24 }

    /*
      B1 69          mov     cl, 69h ; 'i'
      30 88 [4]      xor     byte ptr word_1001E040[eax], cl
      40             inc     eax
      3D A8 01 00 00 cmp     eax, 1A8h
    */
    $decode = { B1 ?? 30 88 [4] 40 3D A8 01 00 00 }
  
  condition:
    all of them
}