BLACKBERRY_Mal_Win32_Chaosransomware_2022

import "pe"

rule BLACKBERRY_Mal_Win32_Chaosransomware_2022 : FILE
{
	meta:
		description = "Detects Ransomware Built by Chaos Ransomware Builder"
		author = "BlackBerry Threat Research"
		id = "1fc57dd4-f020-5eb6-8e60-2bce3edfc512"
		date = "2022-05-10"
		modified = "2022-07-07"
		reference = "https://blogs.blackberry.com/en/2022/05/yashma-ransomware-tracing-the-chaos-family-tree"
		source_url = "https://github.com/mikesxrs/Open-Source-YARA-rules/blob/ec0056f767db98bf6d5fd63877ad51fb54d350e9/Blackberry/Mal_Win32_ChaosRansomware_2022.yar#L3-L45"
		license_url = "N/A"
		logic_hash = "d466570965e22b1bb0f1ca30c725d553d7ccf9e25ce2b546f105002260b1d526"
		score = 75
		quality = 83
		tags = "FILE"
		license = "This Yara rule is provided under the Apache License 2.0 (https://www.apache.org/licenses/LICENSE-2.0) and open to any user or organization, as long as you use it under this license and ensure originator credit in any derivative to The BlackBerry Research & Intelligence Team"

	strings:
		$x1 = "Encrypt" ascii wide
		$x2 = "(?:[13]{1}[a-km-zA-HJ-NP-Z1-9]{26,33}|bc1[a-z0-9]{39,59})" ascii wide
		$x3 = "read" ascii wide
		$r1 = { 20 76 69 72 75 73 }
		$r2 = { 72 00 61 00 6e 00 73 00 6f 00 6d 00 77 00 61 00 72 00 65 }
		$z0 = "deleteShadowCopies" ascii wide
		$z1 = "shadowcopy" ascii wide

	condition:
		uint16( 0 ) == 0x5a4d and filesize < 35KB and pe.imphash ( ) == "f34d5f2d4577ed6d9ceec516c1f5a744" and pe.number_of_sections == 3 and ( ( all of ( $x* ) ) and ( 1 of ( $r* ) ) and ( 1 of ( $z* ) ) )
}