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DITEKSHEN_MALWARE_Win_STOP

Detects STOP ransomware

MalwareStopditekSHen detectionBSD 2-Clause LicenseCompiles with YARA-X
Author
ditekSHen
Date
2020-11-06
Modified
2024-11-01
Score / Quality
75 / 73

What this rule detects

Detects STOP ransomware

Associated malware family: Stop.

Targets: Windows PE.

It defines 13 patterns (12 text, 0 hex, 1 regex).

Summary generated from the rule's metadata and condition.

Rule source

malware-win-stop.yarBSD 2-Clause License
rule DITEKSHEN_MALWARE_Win_STOP : FILE
{
	meta:
		description = "Detects STOP ransomware"
		author = "ditekSHen"
		id = "e928d917-a9d9-5830-938a-59b62608e84c"
		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#L3286-L3309"
		license_url = "https://github.com/ditekshen/detection/blob/e76c93dcdedff04076380ffc60ea54e45b313635/LICENSE.txt"
		logic_hash = "61f7e7c1139c56088b2f58b78ae132ffcfef0f931c15b67ea775b0d5e51d189d"
		score = 75
		quality = 73
		tags = "FILE"
		snort2_sid = "920113"
		snort3_sid = "920111"
		clamav_sig = "MALWARE.Win.Ransomware.STOP"

	strings:
		$x1 = "C:\\SystemID\\PersonalID.txt" fullword wide
		$x2 = "/deny *S-1-1-0:(OI)(CI)(DE,DC)" wide
		$x3 = "e:\\doc\\my work (c++)\\_git\\encryption\\" ascii wide nocase
		$s1 = "\" --AutoStart" fullword ascii wide
		$s2 = "--ForNetRes" fullword wide
		$s3 = "--Admin" fullword wide
		$s4 = "%username%" fullword wide
		$s5 = "?pid=" fullword wide
		$s6 = /&first=(true|false)/ fullword wide
		$s7 = "delself.bat" ascii
		$mutex1 = "{1D6FC66E-D1F3-422C-8A53-C0BBCF3D900D}" fullword ascii
		$mutex2 = "{FBB4BCC6-05C7-4ADD-B67B-A98A697323C1}" fullword ascii
		$mutex3 = "{36A698B9-D67C-4E07-BE82-0EC5B14B4DF5}" fullword ascii

	condition:
		uint16( 0 ) == 0x5a4d and ( ( 2 of ( $x* ) and 1 of ( $mutex* ) ) or ( all of ( $x* ) ) or ( 6 of ( $s* ) and ( 1 of ( $x* ) or 1 of ( $mutex* ) ) ) or ( 9 of them ) )
}

Strings (13 patterns)

IdentifierTypeValueModifiers
$x1text"C:\\SystemID\\PersonalID.txt"fullword wide
$x2text"/deny *S-1-1-0:(OI)(CI)(DE,DC)"wide
$x3text"e:\\doc\\my work (c++)\\_git\\encryption\\"ascii wide nocase
$s1text"\" --AutoStart"fullword ascii wide
$s2text"--ForNetRes"fullword wide
$s3text"--Admin"fullword wide
$s4text"%username%"fullword wide
$s5text"?pid="fullword wide
$s6regex/&first=(true|false)/fullword wide
$s7text"delself.bat"ascii
$mutex1text"{1D6FC66E-D1F3-422C-8A53-C0BBCF3D900D}"fullword ascii
$mutex2text"{FBB4BCC6-05C7-4ADD-B67B-A98A697323C1}"fullword ascii
$mutex3text"{36A698B9-D67C-4E07-BE82-0EC5B14B4DF5}"fullword ascii

Condition

uint16( 0 ) == 0x5a4d and ( ( 2 of ( $x* ) and 1 of ( $mutex* ) ) or ( all of ( $x* ) ) or ( 6 of ( $s* ) and ( 1 of ( $x* ) or 1 of ( $mutex* ) ) ) or ( 9 of them ) )

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • All patterns in ( $x* ) must match.
  • At least 2 patterns in ( $x* ) must match.
  • At least 1 patterns in ( $mutex* ) must match.
  • At least 6 patterns in ( $s* ) must match.
  • At least 1 patterns in ( $x* ) must match.
  • At least 9 patterns in the rule must match.

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References

Licence & attribution

Author: ditekSHen

Source repository: ditekSHen detection @ e76c93dcde

Licence: BSD 2-Clause License (repository licence)

Copyright notice: Copyright 2021 by ditekSHen (https://github.com/ditekshen/detection).

Original rule

Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.

Rule id: e928d917-a9d9-5830-938a-59b62608e84c

Metadata

snort2_sid920113
snort3_sid920111
clamav_sigMALWARE.Win.Ransomware.STOP

Tags:FILE