DITEKSHEN_MALWARE_Win_Fiber

rule DITEKSHEN_MALWARE_Win_Fiber : FILE
{
	meta:
		description = "Detects Fiber .NET injector"
		author = "ditekSHen"
		id = "0e562e2e-cb91-5acf-bb8f-5e7e7d971a3d"
		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#L10788-L10824"
		license_url = "https://github.com/ditekshen/detection/blob/e76c93dcdedff04076380ffc60ea54e45b313635/LICENSE.txt"
		logic_hash = "bd6c2c02272fe59c8d7de533197f15d94b5532d32875f01e3e4bd52506456a34"
		score = 75
		quality = 75
		tags = "FILE"

	strings:
		$x1 = "Fiber.dll" fullword ascii
		$s1 = "-WindowStyle Hidden Copy-Item -Path *.vbs -Destination" wide
		$s2 = "-WindowStyle Hidden {0} -WindowStyle Hidden Start-Sleep 5; Start-Process {1}" wide
		$s3 = "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Run" wide
		$s4 = "WScript.Shell" fullword wide
		$s5 = "{0}_{1:N}.lnk" fullword wide
		$s6 = "notepad.exe,0" fullword wide
		$i1 = "AppLaunch.exe" fullword wide
		$i2 = "aspnet_regbrowsers.exe" fullword wide
		$i3 = "cvtres.exe" fullword wide
		$i4 = "ilasm.exe" fullword wide
		$i5 = "jsc.exe" fullword wide
		$i6 = "MSBuild.exe" fullword wide
		$i7 = "RegAsm.exe" fullword wide
		$i8 = "RegSvcs.exe" fullword wide
		$v1 = "is tampered" wide
		$v2 = "Debugger Detected" wide
		$v3 = "RepositoryUrl" ascii
		$v4 = { 72 00 63 00 65 00 41 00 00 11 56 00 69 00 72 00
                74 00 75 00 61 00 6c 00 20 00 00 0b 41 00 6c 00
                6c 00 6f 00 63 00 00 0d 57 00 72 00 69 00 74 00
                65 00 20 00 00 11 50 00 72 00 6f 00 63 00 65 00
                73 00 73 00 20 00 00 0d 4d 00 65 00 6d 00 6f 00
                72 00 79 00 00 0f 50 00 72 00 6f 00 74 00 65 00
                63 00 74 00 00 0b 4f 00 70 00 65 00 6e 00 20 00
                00 0f 50 00 72 00 6f 00 63 00 65 00 73 00 73 00
                00 0d 43 00 6c 00 6f 00 73 00 65 00 20 00 00 0d
                48 00 61 00 6e 00 64 00 6c 00 65 00 00 0f 6b 00
                65 00 72 00 6e 00 65 00 6c }

	condition:
		uint16( 0 ) == 0x5a4d and ( ( 1 of ( $x* ) and 3 of ( $s* ) and 2 of ( $i* ) ) or ( 4 of ( $s* ) and 4 of ( $i* ) ) or ( 2 of ( $s* ) and 6 of ( $i* ) ) or ( 1 of ( $x* ) and 3 of ( $v* ) ) or ( all of ( $v* ) ) )
}