DITEKSHEN_MALWARE_Win_Covenantgruntstager

rule DITEKSHEN_MALWARE_Win_Covenantgruntstager : FILE
{
	meta:
		description = "Detects Covenant Grunt Stager"
		author = "ditekSHen"
		id = "61495541-ed9c-5227-aa50-cbaeacfb20a2"
		date = "2020-11-06"
		modified = "2024-11-01"
		reference = "https://github.com/ditekshen/detection"
		source_url = "https://github.com/ditekshen/detection/blob/e76c93dcdedff04076380ffc60ea54e45b313635/yara/malware.yar#L5585-L5606"
		license_url = "https://github.com/ditekshen/detection/blob/e76c93dcdedff04076380ffc60ea54e45b313635/LICENSE.txt"
		logic_hash = "638f63f605b21154f062b0f4d0659cd6cd87aee319debb2c1a991a679fec087a"
		score = 75
		quality = 75
		tags = "FILE"

	strings:
		$x1 = "VXNlci1BZ2VudA" ascii wide
		$x2 = "cGFnZT17R1VJRH0mdj0x" ascii wide
		$x3 = "0eXBlPXtHVUlEfSZ2PTE" ascii wide
		$x4 = "tZXNzYWdlPXtHVUlEfSZ2PTE" ascii wide
		$x5 = "L2VuLXVzL" ascii wide
		$x6 = "L2VuLXVzL2luZGV4Lmh0bWw" ascii wide
		$x7 = "L2VuLXVzL2RvY3MuaHRtbD" ascii wide
		$s1 = "ExecuteStager" ascii
		$s2 = "UseCertPinning" fullword ascii
		$s3 = "FromBase64String" fullword ascii
		$s4 = "ToBase64String" fullword ascii
		$s5 = "DownloadString" fullword ascii
		$s6 = "UploadString" fullword ascii
		$s7 = "GetWebRequest" fullword ascii

	condition:
		uint16( 0 ) == 0x5a4d and ( 2 of ( $x* ) or all of ( $s* ) or ( 1 of ( $x* ) and 5 of ( $s* ) ) )
}