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GCTI_Cobaltstrike_Sleeve_Beaconloader_MVF_X86_O_V4_3_V4_4_V4_5_And_V4_6

Cobalt Strike's sleeve/BeaconLoader.MVF.x86.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.x86.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-x86-o-v4-3-v4-4-v4-5-and-v4-6.yarApache License 2.0
rule GCTI_Cobaltstrike_Sleeve_Beaconloader_MVF_X86_O_V4_3_V4_4_V4_5_And_V4_6
{
	meta:
		description = "Cobalt Strike's sleeve/BeaconLoader.MVF.x86.o (MapViewOfFile) Versions 4.3 through at least 4.6"
		author = "gssincla@google.com"
		id = "3f7c0553-989e-53e7-87a9-3fa1c47f4b62"
		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#L61-L111"
		license_url = "https://github.com/chronicle/GCTI/blob/1c5fd42b1895098527fde00c2d9757edf6b303bb/LICENSE"
		hash = "cded3791caffbb921e2afa2de4c04546067c3148c187780066e8757e67841b44"
		logic_hash = "dd831fb01a403213c06e3d07daf3da5f56655619a686149f9d4beec2331fe6ca"
		score = 75
		quality = 85
		tags = ""

	strings:
		$core_sig = {
      C6 45 EC 4D
      C6 45 ED 61
      C6 45 EE 70
      C6 45 EF 56
      C6 45 F0 69
      C6 45 F1 65
      C6 45 F2 77
      C6 45 F3 4F
      C6 45 F4 66
      C6 45 F5 46
      C6 45 F6 69
      C6 45 F7 6C
      C6 45 F8 65
      C6 45 F9 00
    }

	condition:
		all of them
}

Strings (1 patterns)

IdentifierTypeValueModifiers
$core_sighex{ C6 45 EC 4D C6 45 ED 61 C6 45 EE 70 C6 45 EF 56 C6 45 F0 69 C6 45 F1 65 C6 45 F2 77 C6 45 F3 4F C6 45 F4 …

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).

  • cded3791caffbb921e2afa2de4c04546067c3148c187780066e8757e67841b44

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: 3f7c0553-989e-53e7-87a9-3fa1c47f4b62

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