GCTI_Cobaltstrike_Sleeve_Beaconloader_X64_O_V4_3_V4_4_V4_5_And_V4_6

rule GCTI_Cobaltstrike_Sleeve_Beaconloader_X64_O_V4_3_V4_4_V4_5_And_V4_6
{
	meta:
		description = "Cobalt Strike's sleeve/BeaconLoader.x64.o (Base) Versions 4.3 through at least 4.6"
		author = "gssincla@google.com"
		id = "07f751e4-f001-5b95-b229-31fbaa867cea"
		date = "2022-11-18"
		modified = "2022-11-19"
		reference = "https://cloud.google.com/blog/products/identity-security/making-cobalt-strike-harder-for-threat-actors-to-abuse"
		source_url = "https://github.com/chronicle/GCTI/blob/1c5fd42b1895098527fde00c2d9757edf6b303bb/YARA/CobaltStrike/CobaltStrike__Sleeve_BeaconLoader_all.yara#L458-L555"
		license_url = "https://github.com/chronicle/GCTI/blob/1c5fd42b1895098527fde00c2d9757edf6b303bb/LICENSE"
		hash = "ac090a0707aa5ccd2c645b523bd23a25999990cf6895fce3bfa3b025e3e8a1c9"
		logic_hash = "50d9da466e2c074b3fb634203c8840d45da8f8e3094790d7c4354a5703b583ef"
		score = 75
		quality = 85
		tags = ""

	strings:
		$core_sig = {
      33 C0
      83 F8 01
      74 63
      48 8B 44 24 20
      0F B7 00
      3D 4D 5A 00 00
      75 45
      48 8B 44 24 20
      48 63 40 3C
      48 89 44 24 28
      48 83 7C 24 28 40
      72 2F
      48 81 7C 24 28 00 04 00 00
      73 24
      48 8B 44 24 20
      48 8B 4C 24 28
      48 03 C8
      48 8B C1
      48 89 44 24 28
      48 8B 44 24 28
      81 38 50 45 00 00
      75 02
    }
		$deobfuscator = {
      8B 04 24
      FF C0
      89 04 24
      8B 44 24 28
      39 04 24
      73 20
      8B 04 24
      0F B6 4C 24 30
      48 8B 54 24 20
      0F BE 04 02
      33 C1
      8B 0C 24
      48 8B 54 24 20
      88 04 0A
    }

	condition:
		$core_sig and not $deobfuscator
}