SEKOIA_Apt_Kimsuky_Toddlershark_Obfuscated

rule SEKOIA_Apt_Kimsuky_Toddlershark_Obfuscated : FILE
{
	meta:
		description = "Detects obfuscated version of Kimsuky TODDLERSHARK vbs malware"
		author = "Sekoia.io"
		id = "9ab82466-4f38-4597-b75b-13252e180c70"
		date = "2024-03-06"
		modified = "2024-12-19"
		reference = "https://github.com/SEKOIA-IO/Community"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/apt_kimsuky_toddlershark_obfuscated.yar#L1-L18"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		logic_hash = "5f067ce32e7fee5cf481d82bb98f4ae10bd7187078bc111b08fc58d043954152"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$s1 = { 3a 20 [3-10] 20 3d 20 22 [3-30] 22 3a }
		$s2 = { 45 78 65 63 75 74 65 28  [3-15] 28 22 }
		$s3 = { 50 72 69 76 61 74 65 20 46 75 6e 63 74 69 6f 6e 20 [3-15] 28 42 79 56 61 6c 20 [3-15] 29 3a }
		$s4 = "& Chr(\"&H\" & Mid("

	condition:
		#s4== 1 and #s3 == 1 and #s2 == 1 and #s1 > 20 and filesize < 1MB
}