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DITEKSHEN_MALWARE_Win_Epsilon

Detects Epsilon ransomware

MalwareEpsilonditekSHen detectionBSD 2-Clause LicenseCompila con YARA-X
Autor
ditekSHen
Fecha
2020-11-06
Modificada
2024-11-01
Puntuación / Calidad
75 / 75

Qué detecta esta regla

Detects Epsilon ransomware

Familia de malware asociada: Epsilon.

Objetivos: PE de Windows.

Define 10 patrones (8 de texto, 2 hex, 0 regex).

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

Código de la regla

malware-win-epsilon.yarBSD 2-Clause License
rule DITEKSHEN_MALWARE_Win_Epsilon : FILE
{
	meta:
		description = "Detects Epsilon ransomware"
		author = "ditekSHen"
		id = "c5561a0d-85ac-5137-a97e-310aa03eb787"
		date = "2020-11-06"
		modified = "2024-11-01"
		reference = "https://github.com/ditekshen/detection"
		source_url = "https://github.com/ditekshen/detection/blob/e76c93dcdedff04076380ffc60ea54e45b313635/yara/malware.yar#L4137-L4169"
		license_url = "https://github.com/ditekshen/detection/blob/e76c93dcdedff04076380ffc60ea54e45b313635/LICENSE.txt"
		logic_hash = "cc4481ddb6f5fd52a0bc901dde4c34ccf79024cd68605245df0dcbea22d0adee"
		score = 75
		quality = 75
		tags = "FILE"

	strings:
		$s1 = ".Speak \"" wide
		$s2 = "chkUpdateRegistry" fullword wide
		$s3 = "/C choice /C Y /N /D Y /T 1 & Del \"" fullword wide
		$s4 = "CreateObject(\"sapi.spvoice\")" fullword wide
		$s5 = "READ_ME.hta" wide
		$s6 = "WScript.Sleep(" wide
		$s7 = "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Run" fullword wide
		$s8 = "<div class='bold'>Files are encrypted* but not deleted.</div>" ascii
		$e1 = { 72 00 75 00 6e 00 64 00 6c 00 6c 00 2e 00 65 00
                78 00 65 00 00 09 2e 00 74 00 78 00 74 00 00 09
                2e 00 64 00 6f 00 63 00 00 0b 2e 00 64 00 6f 00
                63 00 78 00 00 09 2e 00 78 00 6c 00 73 00 00 0d
                2e 00 69 00 6e 00 64 00 65 00 78 00 00 09 2e 00
                70 00 64 00 66 00 00 09 2e 00 7a 00 69 00 70 00
                00 09 2e 00 72 00 61 00 72 00 00 09 2e 00 63 00
                73 00 73 00 00 09 2e 00 6c 00 6e 00 6b 00 00 0b
                2e 00 78 00 6c 00 73 00 78 00 00 09 2e 00 70 00
                70 00 74 00 00 0b 2e 00 70 00 70 00 74 00 78 00
                00 09 2e 00 6f 00 64 00 }
		$e2 = { 68 00 74 00 6d 00 00 07 2e 00 6d 00 6c 00 00 07
                43 00 3a 00 5c 00 00 07 44 00 3a 00 5c 00 00 07
                45 00 3a 00 5c 00 00 07 46 00 3a 00 5c 00 00 07
                47 00 3a 00 5c 00 00 07 5a 00 3a 00 5c 00 00 07
                41 00 3a 00 5c 00 00 0f 63 00 6d 00 64 00 2e 00
                65 00 78 00 65 }

	condition:
		uint16( 0 ) == 0x5a4d and ( 6 of ( $s* ) or ( all of ( $e* ) and 4 of ( $s* ) ) )
}

Cadenas (10 patrones)

IdentificadorTipoValorModificadores
$s1texto".Speak \""wide
$s2texto"chkUpdateRegistry"fullword wide
$s3texto"/C choice /C Y /N /D Y /T 1 & Del \""fullword wide
$s4texto"CreateObject(\"sapi.spvoice\")"fullword wide
$s5texto"READ_ME.hta"wide
$s6texto"WScript.Sleep("wide
$s7texto"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Run"fullword wide
$s8texto"<div class='bold'>Files are encrypted* but not deleted.</div>"ascii
$e1hex{ 72 00 75 00 6e 00 64 00 6c 00 6c 00 2e 00 65 00 78 00 65 00 00 09 2e 00 74 00 78 00 74 00 00 09 2e 00 64 00 6f 00 63 00 00 0b …
$e2hex{ 68 00 74 00 6d 00 00 07 2e 00 6d 00 6c 00 00 07 43 00 3a 00 5c 00 00 07 44 00 3a 00 5c 00 00 07 45 00 3a 00 5c 00 00 07 46 00 …

Condición

uint16( 0 ) == 0x5a4d and ( 6 of ( $s* ) or ( all of ( $e* ) and 4 of ( $s* ) ) )

En palabras sencillas (Heurística)

  • El archivo debe empezar por «MZ»: un ejecutable de Windows (PE).
  • Deben coincidir todos los patrones de ( $e* ).
  • Deben coincidir al menos 6 patrones de ( $s* ).
  • Deben coincidir al menos 4 patrones de ( $s* ).

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Referencias

Licencia y atribución

Autor: ditekSHen

Repositorio de origen: ditekSHen detection @ e76c93dcde

Licencia: BSD 2-Clause License (licencia del repositorio)

Aviso de copyright: Copyright 2021 by ditekSHen (https://github.com/ditekshen/detection).

Regla original

Obtenida a través de YARA Forge 20260927, que añade a los nombres el prefijo de la fuente y campos meta normalizados.

Id de la regla: c5561a0d-85ac-5137-a97e-310aa03eb787

Etiquetas:FILE