YARA · CAPE Sandbox (CAPEv2)

CAPE_Buerloader

No description has been set in the source file - CAPE

GenericCAPE Sandbox (CAPEv2)GNU General Public License v3.0Compiles with YARA-X

Author: kevoreilly & Rony (@r0ny_123)
Date: 2020-10-29
Modified: 2022-05-31
Score / Quality: 75 / 70

What this rule detects

No description has been set in the source file - CAPE

Targets: Windows PE.

It defines 3 patterns (0 text, 3 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar

buerloader.yarGNU General Public License v3.0

rule CAPE_Buerloader : FILE
{
	meta:
		description = "No description has been set in the source file - CAPE"
		author = "kevoreilly & Rony (@r0ny_123)"
		id = "95a9b4d7-db1e-50cd-bc08-01e4e4fd6dc4"
		date = "2020-10-29"
		modified = "2022-05-31"
		reference = "https://github.com/kevoreilly/CAPEv2"
		source_url = "https://github.com/kevoreilly/CAPEv2/blob/6b15e76f28cd83fd1187da6c9aaaad2174255356/data/yara/CAPE/BuerLoader.yar#L1-L12"
		license_url = "https://github.com/kevoreilly/CAPEv2/blob/6b15e76f28cd83fd1187da6c9aaaad2174255356/LICENSE"
		logic_hash = "05c1f008f0a2bb8232867977fb23a5ae8312f10f0637c6265561052596319c29"
		score = 75
		quality = 70
		tags = "FILE"
		cape_type = "BuerLoader Payload"

	strings:
		$trap = {0F 31 89 45 ?? 6A 00 8D 45 ?? 8B CB 50 E8 [4] 0F 31}
		$decode = {8A 0E 84 C9 74 0E 8B D0 2A 0F 46 88 0A 42 8A 0E 84 C9 75 F4 5F 5E 5D C2 04 00}
		$op = {33 C0 85 D2 7E 1? 3B C7 7D [0-15] 40 3B C2 7C ?? EB 02}

	condition:
		uint16( 0 ) == 0x5A4D and 2 of them
}

Strings (3 patterns)

Identifier	Type	Value
$trap	hex	{0F 31 89 45 ?? 6A 00 8D 45 ?? 8B CB 50 E8 [4] 0F 31}
$decode	hex	{8A 0E 84 C9 74 0E 8B D0 2A 0F 46 88 0A 42 8A 0E 84 C9 75 F4 5F 5E 5D C2 04 00}
$op	hex	{33 C0 85 D2 7E 1? 3B C7 7D [0-15] 40 3B C2 7C ?? EB 02}

Condition

uint16( 0 ) == 0x5A4D and 2 of them

In plain words (Heuristic)

The file must start with “MZ” — a Windows executable (PE).
At least 2 patterns in the rule must match.

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References

https://github.com/kevoreilly/CAPEv2

Licence & attribution

Author: kevoreilly & Rony (@r0ny_123)

Source repository: CAPE Sandbox (CAPEv2) @ 6b15e76f28

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

Original rule

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

Rule id: 95a9b4d7-db1e-50cd-bc08-01e4e4fd6dc4

Metadata

cape_type	BuerLoader Payload

Tags:FILE