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YARA · CAPE Sandbox (CAPEv2)

CAPE_Obfuscar

Obfuscar xor routime

GenericCAPE Sandbox (CAPEv2)GNU General Public License v3.0Compiles with YARA-X
Author
kevoreilly
Date
2025-03-07
Score / Quality
75 / 70

What this rule detects

Obfuscar xor routime

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
obfuscar.yarGNU General Public License v3.0
rule CAPE_Obfuscar : FILE
{
	meta:
		description = "Obfuscar xor routime"
		author = "kevoreilly"
		id = "81eeb62f-578f-5c75-bc96-091d5727a20a"
		date = "2025-03-07"
		modified = "2025-03-07"
		reference = "https://github.com/kevoreilly/CAPEv2"
		source_url = "https://github.com/kevoreilly/CAPEv2/blob/6b15e76f28cd83fd1187da6c9aaaad2174255356/data/yara/CAPE/Obfuscar.yar#L1-L12"
		license_url = "https://github.com/kevoreilly/CAPEv2/blob/6b15e76f28cd83fd1187da6c9aaaad2174255356/LICENSE"
		logic_hash = "54581e83e5fa13fae4bda74016b3fa1d18c92e2659f493ebe54d70fd5f77bba5"
		score = 75
		quality = 70
		tags = "FILE"

	strings:
		$decode = {06 91 06 61 20 [4] 61 D2 9C 06 17 58 0A 06 7E [4] 8E 69 FE 04 2D ?? 2A}

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

Strings (1 patterns)

IdentifierTypeValueModifiers
$decodehex{06 91 06 61 20 [4] 61 D2 9C 06 17 58 0A 06 7E [4] 8E 69 FE 04 2D ?? 2A}

Condition

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

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • At least one pattern in the rule must match.

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References

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: 81eeb62f-578f-5c75-bc96-091d5727a20a

Tags:FILE

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