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GCTI_Cobaltstrike_Sleeve_Beaconloader_MVF_X64_O_V4_3_V4_4_V4_5_And_V4_6

Cobalt Strike's sleeve/BeaconLoader.MVF.x64.o (MapViewOfFile) Versions 4.3 through at least 4.6

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 sleeve/BeaconLoader.MVF.x64.o (MapViewOfFile) Versions 4.3 through at least 4.6

Associated malware family: Cobalt Strike.

It defines 1 patterns (0 text, 1 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

cobaltstrike-sleeve-beaconloader-mvf-x64-o-v4-3-v4-4-v4-5-and-v4-6.yarApache License 2.0
rule GCTI_Cobaltstrike_Sleeve_Beaconloader_MVF_X64_O_V4_3_V4_4_V4_5_And_V4_6
{
	meta:
		description = "Cobalt Strike's sleeve/BeaconLoader.MVF.x64.o (MapViewOfFile) Versions 4.3 through at least 4.6"
		author = "gssincla@google.com"
		id = "38e063db-3d76-5a94-812a-945fcf46a232"
		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#L326-L374"
		license_url = "https://github.com/chronicle/GCTI/blob/1c5fd42b1895098527fde00c2d9757edf6b303bb/LICENSE"
		hash = "9d5b6ccd0d468da389657309b2dc325851720390f9a5f3d3187aff7d2cd36594"
		logic_hash = "6224000342d87041fd3336656897479c644e94ea36fc061c27fcd64233047c2c"
		score = 75
		quality = 85
		tags = ""

	strings:
		$core_sig = {
      C6 44 24 58 4D
      C6 44 24 59 61
      C6 44 24 5A 70
      C6 44 24 5B 56
      C6 44 24 5C 69
      C6 44 24 5D 65
      C6 44 24 5E 77
      C6 44 24 5F 4F
      C6 44 24 60 66
      C6 44 24 61 46
      C6 44 24 62 69
      C6 44 24 63 6C
      C6 44 24 64 65
    }

	condition:
		all of them
}

Strings (1 patterns)

IdentifierTypeValueModifiers
$core_sighex{ C6 44 24 58 4D C6 44 24 59 61 C6 44 24 5A 70 C6 44 24 5B 56 C6 44 24 5C 69 C6 44 24 5D 65 C6 44 24 5E 77 C6 44 …

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).

  • 9d5b6ccd0d468da389657309b2dc325851720390f9a5f3d3187aff7d2cd36594

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: 38e063db-3d76-5a94-812a-945fcf46a232

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