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YARA · ditekSHen detection

DITEKSHEN_MALWARE_Win_Badjoke

Detects BadJoke / Witch

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

What this rule detects

Detects BadJoke / Witch

Associated malware family: Badjoke.

Targets: Windows PE.

It defines 8 patterns (8 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
malware-win-badjoke.yarBSD 2-Clause License
rule DITEKSHEN_MALWARE_Win_Badjoke : FILE
{
	meta:
		description = "Detects BadJoke / Witch"
		author = "ditekSHen"
		id = "082727d5-618f-542d-93ca-ba93be16cd80"
		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#L8816-L8831"
		license_url = "https://github.com/ditekshen/detection/blob/e76c93dcdedff04076380ffc60ea54e45b313635/LICENSE.txt"
		logic_hash = "4699a772bcd50d2fe43740df59a4c56598ba43ebcc18acbf8ec401b6f5a01fe6"
		score = 75
		quality = 75
		tags = "FILE"

	strings:
		$s1 = "msdownld.tmp" fullword ascii
		$s2 = "UPDFILE%lu" fullword ascii
		$s3 = "Command.com /c %s" fullword ascii
		$s4 = "launch.cmd" fullword ascii
		$s5 = "virus.vbs" fullword ascii
		$s6 = "virus.py" fullword ascii
		$m1 = "Message from Google Virus" ascii
		$m2 = "you cannot get rid of this virus" ascii

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

Strings (8 patterns)

IdentifierTypeValueModifiers
$s1text"msdownld.tmp"fullword ascii
$s2text"UPDFILE%lu"fullword ascii
$s3text"Command.com /c %s"fullword ascii
$s4text"launch.cmd"fullword ascii
$s5text"virus.vbs"fullword ascii
$s6text"virus.py"fullword ascii
$m1text"Message from Google Virus"ascii
$m2text"you cannot get rid of this virus"ascii

Condition

uint16( 0 ) == 0x5a4d and ( all of ( $m* ) or all of ( $s* ) or ( 1 of ( $m* ) and 2 of ( $s* ) ) )

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • All patterns in ( $m* ) must match.
  • All patterns in ( $s* ) must match.
  • At least 1 patterns in ( $m* ) must match.
  • At least 2 patterns in ( $s* ) 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: 082727d5-618f-542d-93ca-ba93be16cd80

Tags:FILE

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