YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_MAL_RANSOM_Lockbit_Indicators_Feb24

Detects Lockbit ransomware samples mentioned in a HuntressLabs report on the exploitation of ScreenConnect vulnerability CVE-2024-1708 and CVE-2024-1709

MalwareLockbitSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compila con YARA-X

Autor: Florian Roth
Fecha: 2024-02-23
Modificada: 2024-04-24
Puntuación / Calidad: 75 / 85

Qué detecta esta regla

Detects Lockbit ransomware samples mentioned in a HuntressLabs report on the exploitation of ScreenConnect vulnerability CVE-2024-1708 and CVE-2024-1709

Familia de malware asociada: Lockbit.

Objetivos: PE de Windows.

Define 3 patrones (0 de texto, 3 hex, 0 regex). Módulos YARA usados: pe.

Resumen generado a partir de los metadatos y la condición de la regla.

Código de la regla

Descargar .yar

Incluye los imports necesarios para compilarla por sí sola.

mal-ransom-lockbit-indicators-feb24.yarDetection Rule License 1.1

import "pe"

rule SIGNATURE_BASE_MAL_RANSOM_Lockbit_Indicators_Feb24 : CVE_2024_1708 CVE_2024_1709 FILE
{
	meta:
		description = "Detects Lockbit ransomware samples mentioned in a HuntressLabs report on the exploitation of ScreenConnect vulnerability CVE-2024-1708 and CVE-2024-1709"
		author = "Florian Roth"
		id = "108430c8-4fe5-58a1-b709-539b257c120c"
		date = "2024-02-23"
		modified = "2024-04-24"
		reference = "https://www.huntress.com/blog/slashandgrab-screen-connect-post-exploitation-in-the-wild-cve-2024-1709-cve-2024-1708"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/expl_connectwise_screenconnect_vuln_feb24.yar#L208-L228"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		hash = "a50d9954c0a50e5804065a8165b18571048160200249766bfa2f75d03c8cb6d0"
		logic_hash = "e4cd6b1a1bc57bf25c71f6bc228f45e4a996f9d9d391aeb3dda9c7d7857610bc"
		score = 75
		quality = 85
		tags = "CVE-2024-1708, CVE-2024-1709, FILE"

	strings:
		$op1 = { 76 c1 95 8b 18 00 93 56 bf 2b 88 71 4c 34 af b1 a5 e9 77 46 c3 13 }
		$op2 = { e0 02 10 f7 ac 75 0e 18 1b c2 c1 98 ac 46 }
		$op3 = { 8b c6 ab 53 ff 15 e4 57 42 00 ff 45 fc eb 92 ff 75 f8 ff 15 f4 57 42 00 }

	condition:
		uint16( 0 ) == 0x5a4d and filesize < 500KB and ( pe.imphash ( ) == "914685b69f2ac2ff61b6b0f1883a054d" or 2 of them ) or all of them
}

Cadenas (3 patrones)

Identificador	Tipo	Valor
$op1	hex	{ 76 c1 95 8b 18 00 93 56 bf 2b 88 71 4c 34 af b1 a5 e9 77 46 c3 13 }
$op2	hex	{ e0 02 10 f7 ac 75 0e 18 1b c2 c1 98 ac 46 }
$op3	hex	{ 8b c6 ab 53 ff 15 e4 57 42 00 ff 45 fc eb 92 ff 75 f8 ff 15 f4 57 42 00 }

Condición

uint16( 0 ) == 0x5a4d and filesize < 500KB and ( pe.imphash ( ) == "914685b69f2ac2ff61b6b0f1883a054d" or 2 of them ) or all of them

En palabras sencillas (Heurística)

El archivo debe empezar por «MZ»: un ejecutable de Windows (PE).
El archivo debe ocupar menos de 500KB (un límite barato que descarta archivos grandes).
Deben coincidir todos los patrones de la regla.
Deben coincidir al menos 2 patrones de la regla.
Usa el módulo pe.
Comprueba el hash de importaciones PE (imphash).