DITEKSHEN_MALWARE_Win_Arcrypt

rule DITEKSHEN_MALWARE_Win_Arcrypt : FILE
{
	meta:
		description = "Detects ARCrypt / ChileLocker ransomware"
		author = "ditekSHen"
		id = "a53bbae6-a321-549d-9d45-e1a408d08740"
		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#L10373-L10399"
		license_url = "https://github.com/ditekshen/detection/blob/e76c93dcdedff04076380ffc60ea54e45b313635/LICENSE.txt"
		logic_hash = "cc9fa68d093fdf9745a06beb28e29108cb2ba846122ce097ad892213b1edba25"
		score = 75
		quality = 75
		tags = "FILE"

	strings:
		$c1 = "readme_for_unlock.txt" wide
		$c2 = "vssadmin.exe delete shadows /all /quiet" wide
		$c3 = "START /b \"\" cmd /c wmic /node:" wide
		$c4 = "START /b \"\" cmd /c DEL \"" wide
		$c5 = "process call create cmd /c START" wide
		$c6 = "net config server /autodisconnect:" wide
		$c7 = "/NOBREAK>NUL) ELSE (START /b \"\" cmd /c DEL \"%~f" ascii
		$c8 = ":\\_ARC\\_WorkSolution\\cryptopp" ascii
		$e1 = /\.crYpt([A-F]{0,1}(\d+)?)?/ fullword wide
		$e2 = ".dnt___.crYpt" wide nocase
		$s1 = "create_directory" fullword ascii
		$s2 = "create_directories" fullword ascii
		$s3 = "NoClose" fullword ascii
		$s4 = "StartMenuLogOff" fullword ascii
		$s5 = "NoLogOff" fullword ascii
		$s6 = "DisableTaskMgr" fullword ascii
		$s7 = "DisableChangePassword" fullword ascii
		$s8 = "HideFastUserSwitching" fullword ascii
		$s9 = "RemotePath" fullword ascii

	condition:
		uint16( 0 ) == 0x5a4d and ( 5 of ( $c* ) or 7 of ( $s* ) or ( 3 of ( $c* ) and 4 of ( $s* ) ) or ( 1 of ( $e* ) and ( 1 of ( $c* ) and 1 of ( $s* ) ) ) or ( all of ( $e* ) and ( 1 of ( $c* ) or 1 of ( $s* ) ) ) )
}