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YARA · CAPE Sandbox (CAPEv2)

CAPE_Anticuckoo

AntiCuckoo bypass: https://github.com/therealdreg/anticuckoo

GenericCAPE Sandbox (CAPEv2)GNU General Public License v3.0Compiles with YARA-X
Author
kevoreilly
Date
2023-03-17
Score / Quality
75 / 70

What this rule detects

AntiCuckoo bypass: https://github.com/therealdreg/anticuckoo

Targets: Windows PE.

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

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
anticuckoo.yarGNU General Public License v3.0
rule CAPE_Anticuckoo : FILE
{
	meta:
		description = "AntiCuckoo bypass: https://github.com/therealdreg/anticuckoo"
		author = "kevoreilly"
		id = "e221e57b-313e-5998-a3fc-5b4e9671b989"
		date = "2023-03-17"
		modified = "2023-03-17"
		reference = "https://github.com/kevoreilly/CAPEv2"
		source_url = "https://github.com/kevoreilly/CAPEv2/blob/6b15e76f28cd83fd1187da6c9aaaad2174255356/analyzer/windows/data/yara/AntiCuckoo.yar#L1-L12"
		license_url = "https://github.com/kevoreilly/CAPEv2/blob/6b15e76f28cd83fd1187da6c9aaaad2174255356/LICENSE"
		hash = "ad5e52f144bb4a1dae3090978c6ecb4c7732538c9b62a6cedd32eccee6094be5"
		logic_hash = "a039aeca2dae44980e8bffafacfda90975e107001be50f11ac916b35ad43592e"
		score = 75
		quality = 70
		tags = "FILE"
		cape_options = "bp0=$HKActivOldStackCrash+36,action0=jmp,count=1"

	strings:
		$HKActivOldStackCrash = {5B 81 FB FA FA FA FA 74 01 41 3B E0 75 ?? 83 E9 0B 83 F9 04 7F 04 C6 45 ?? 00 89 4D ?? 89 65 ?? 80 7D ?? 00 74}

	condition:
		uint16( 0 ) == 0x5A4D and all of them
}

Strings (1 patterns)

IdentifierTypeValueModifiers
$HKActivOldStackCrashhex{5B 81 FB FA FA FA FA 74 01 41 3B E0 75 ?? 83 E9 0B 83 F9 04 7F 04 C6 45 ?? 00 89 4D ?? 89 65 ?? 80 7D ?? 00 74}

Condition

uint16( 0 ) == 0x5A4D and all of them

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • 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).

  • ad5e52f144bb4a1dae3090978c6ecb4c7732538c9b62a6cedd32eccee6094be5

Licence & attribution

Author: kevoreilly

Source repository: CAPE Sandbox (CAPEv2) @ 6b15e76f28

Licence: GNU General Public License v3.0 (repository licence)

Copyright notice: Cuckoo Sandbox is copyrighted by the Cuckoo Foundation.

Original rule

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

Rule id: e221e57b-313e-5998-a3fc-5b4e9671b989

Metadata

cape_optionsbp0=$HKActivOldStackCrash+36,action0=jmp,count=1

Tags:FILE

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