SEKOIA_Malware_Valleyrat_Downloader_Strings

rule SEKOIA_Malware_Valleyrat_Downloader_Strings : FILE
{
	meta:
		description = "Detects ValleyRat downloader"
		author = "Sekoia.io"
		id = "12985f34-f894-402b-80d1-5d6b2486d730"
		date = "2024-06-11"
		modified = "2024-12-19"
		reference = "https://github.com/SEKOIA-IO/Community"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/malware_valleyrat_downloader_strings.yar#L1-L20"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		logic_hash = "321683ac5bdec626cf140cb50507fb03aea2a32635eb6cec884a3fa43c1a9d91"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$ = { 43 00 3a 00 5c [0-30]
        5c 00 4e 00 54 00 55
        00 53 00 45 00 52 00
        2e 00 44 00 58 }

	condition:
		uint16be( 0 ) == 0x4d5a and filesize < 2MB and all of them
}