SEKOIA_Apt_Gamaredon_Stealer_Obfuscation_1

rule SEKOIA_Apt_Gamaredon_Stealer_Obfuscation_1 : FILE
{
	meta:
		description = "Matches the Gamaredon Stealer obfuscation"
		author = "Sekoia.io"
		id = "a6197d16-8ed1-410b-8814-d7eff9a8096c"
		date = "2022-02-04"
		modified = "2024-12-19"
		reference = "https://github.com/SEKOIA-IO/Community"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/apt_gamaredon_stealer_obfuscation_1.yar#L1-L18"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		logic_hash = "7f6a5f8af73c4eb7debbadfd22232ad4e3f44e3aae36c3d624ce7a1a050e8782"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$s1 = { 76 61 72 20 [5-30] 3d 20 6e 65 77 20 6f 62 6a 65 63 74 5b 5d 20 7b 20 [2-10] 2c 20 [2-10] 2c 20 [2-10] 2c 20 [2-10] 2c 20 [2-10] 2c 20 [2-10] 20 7d 3b }
		$s2 = { 66 6f 72 28 69 6e 74 20 [5-30] 20 3d 20 30 3b 20 [5-30] 20 3c 20 31 30 3b 20 [5-30] 2b 2b 29 }

	condition:
		uint16be( 0 ) == 0x4d5a and filesize > 100MB and ( #s1 > 100 or #s2 > 100 )
}