SEKOIA_Apt_Kimsuky_Powershell

rule SEKOIA_Apt_Kimsuky_Powershell : FILE
{
	meta:
		description = "Powershell scripts used by Kimsuky. If size < 3KB ok. If between 3 and 15, a check is needed"
		author = "Sekoia.io"
		id = "b7f812e0-d08b-40fe-908a-dc5765d6bc66"
		date = "2024-09-23"
		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_powershell.yar#L1-L21"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		hash = "6babb53d881448dc58dd7c32fcd4208a"
		hash = "29ec7a4495ea512d44d33c9847893200"
		hash = "fde68771cebd7ecd81721b0dff5b7869"
		hash = "0c3fd7f45688d5ddb9f0107877ce2fbd"
		hash = "1a1723be720c1d9cd57cf4a6a112df79"
		logic_hash = "7436d8cba8a8caaf95786c38c4ceee4426dc7e36ae3eeed5d3162310cd76091d"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$ = ".ToCharArray();[array]::Reverse(" ascii
		$ = ");$res = -join ($bytes -as [char[]]);Invoke-Expression $res;" ascii

	condition:
		all of them and filesize < 15KB
}