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GCTI_Cobaltstrike_Resources_Bypassuac_X64_Dll_V3_3_To_V3_14_And_Sleeve_Bypassuac_X64_Dll_V4_0_And_V4_X

Cobalt Strike's resources/bypassuac-x64.dll from v3.3 to v3.14 (64-bit version) and sleeve/bypassuac.x64.dll from v4.0 to at least v4.4

Hack toolCobalt StrikeGoogle Cloud Threat Intelligence (GCTI)Apache License 2.0Compiles with YARA-X
Author
gssincla@google.com
Date
2022-11-18
Modified
2022-11-19
Score / Quality
75 / 85

What this rule detects

Cobalt Strike's resources/bypassuac-x64.dll from v3.3 to v3.14 (64-bit version) and sleeve/bypassuac.x64.dll from v4.0 to at least v4.4

Associated malware family: Cobalt Strike.

It defines 2 patterns (0 text, 2 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

cobaltstrike-resources-bypassuac-x64-dll-v3-3-to-v3-14-and-sleeve-bypassuac-x64-dll-v4-0-and-v4-x.yarApache License 2.0
rule GCTI_Cobaltstrike_Resources_Bypassuac_X64_Dll_V3_3_To_V3_14_And_Sleeve_Bypassuac_X64_Dll_V4_0_And_V4_X
{
	meta:
		description = "Cobalt Strike's resources/bypassuac-x64.dll from v3.3 to v3.14 (64-bit version) and sleeve/bypassuac.x64.dll from v4.0 to at least v4.4"
		author = "gssincla@google.com"
		id = "eef83901-63d9-55a3-b115-03f420416177"
		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__Resources_Bypassuac_x64_Dll_v3_3_to_v3_14_and_Sleeve_Bypassuac_x64_Dll_v4_0_and_v4_x.yara#L17-L86"
		license_url = "https://github.com/chronicle/GCTI/blob/1c5fd42b1895098527fde00c2d9757edf6b303bb/LICENSE"
		hash = "9ecf56e9099811c461d592c325c65c4f9f27d947cbdf3b8ef8a98a43e583aecb"
		logic_hash = "d76e3601f61ae164a8df9048d59d15cd6913e64adb93132244e83f40bf67d86a"
		score = 75
		quality = 85
		tags = ""

	strings:
		$deleteFileCOM = {
			48 8B [5]
			45 33 ??
			48 8B ??
			FF 90 90 00 00 00
			85 C0
			75 ??
			48 8B [5]
			48 8B ??
			FF 92 A8 00 00 00
			85 C0
		}
		$copyFileCOM = {
			48 8B [5]
			4C 8B [5]
			48 8B [5]
			48 8B ??
			4C 8B ??
			48 89 [3]
			FF 90 80 00 00 00
			85 C0
			0F 85 [4]
			48 8B [5]
			48 8B 11
			FF 92 A8 00 00 00
		}

	condition:
		all of them
}

Strings (2 patterns)

IdentifierTypeValueModifiers
$deleteFileCOMhex{ 48 8B [5] 45 33 ?? 48 8B ?? FF 90 90 00 00 00 85 C0 75 ?? 48 8B [5] 48 8B ?? FF 92 A8 00 00 00 85 C0 }
$copyFileCOMhex{ 48 8B [5] 4C 8B [5] 48 8B [5] 48 8B ?? 4C 8B ?? 48 89 [3] FF 90 80 00 00 00 85 C0 0F 85 [4] 48 8B [5] 48 8B 11 FF 92 A8 00 …

Condition

all of them

In plain words (Heuristic)

  • All patterns in the rule must match.

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References

Sample hashes

Hashes of samples the author lists in the rule's meta (look them up in your threat-intelligence platform).

  • 9ecf56e9099811c461d592c325c65c4f9f27d947cbdf3b8ef8a98a43e583aecb

Licence & attribution

Author: gssincla@google.com

Source repository: Google Cloud Threat Intelligence (GCTI) @ 1c5fd42b18

Licence: Apache License 2.0 (repository licence)

Original rule

Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.

Rule id: eef83901-63d9-55a3-b115-03f420416177

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