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CAPE_Buerloader_1

BuerLoader RDTSC Trap Bypass

GenericCAPE Sandbox (CAPEv2)GNU General Public License v3.0Compiles with YARA-X
Author
kevoreilly
Date
2021-03-13
Score / Quality
75 / 70

What this rule detects

BuerLoader RDTSC Trap Bypass

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
buerloader-1.yarGNU General Public License v3.0
rule CAPE_Buerloader_1 : FILE
{
	meta:
		description = "BuerLoader RDTSC Trap Bypass"
		author = "kevoreilly"
		id = "38f01199-6bd2-5519-b570-8c0f46e74286"
		date = "2021-03-13"
		modified = "2021-03-13"
		reference = "https://github.com/kevoreilly/CAPEv2"
		source_url = "https://github.com/kevoreilly/CAPEv2/blob/6b15e76f28cd83fd1187da6c9aaaad2174255356/analyzer/windows/data/yara/BuerLoader.yar#L1-L11"
		license_url = "https://github.com/kevoreilly/CAPEv2/blob/6b15e76f28cd83fd1187da6c9aaaad2174255356/LICENSE"
		logic_hash = "6f9f9b4c01251c0643c61701084cca2bdfeea08ca95f982355565cf05483d940"
		score = 75
		quality = 70
		tags = "FILE"
		cape_options = "bp0=$trap+43,action0=skip,count=0"

	strings:
		$trap = {0F 31 89 45 ?? 6A 00 8D 45 ?? 8B CB 50 E8 [4] 0F 31}

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

Strings (1 patterns)

IdentifierTypeValueModifiers
$traphex{0F 31 89 45 ?? 6A 00 8D 45 ?? 8B CB 50 E8 [4] 0F 31}

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: 38f01199-6bd2-5519-b570-8c0f46e74286

Metadata

cape_optionsbp0=$trap+43,action0=skip,count=0

Tags:FILE

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