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DITEKSHEN_MALWARE_Win_Beastdoor

Detects Beastdoor backdoor

MalwareBeastdoorditekSHen 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 Beastdoor backdoor

Associated malware family: Beastdoor.

Targets: Windows PE.

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

Summary generated from the rule's metadata and condition.

Rule source

malware-win-beastdoor.yarBSD 2-Clause License
rule DITEKSHEN_MALWARE_Win_Beastdoor : FILE
{
	meta:
		description = "Detects Beastdoor backdoor"
		author = "ditekSHen"
		id = "b271d53e-2693-5a93-825a-ef32f72a4b01"
		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#L6064-L6084"
		license_url = "https://github.com/ditekshen/detection/blob/e76c93dcdedff04076380ffc60ea54e45b313635/LICENSE.txt"
		logic_hash = "d9a72717d124bcf1e3b95850cd524e577abe96a094586a5555faadba78fcb9ad"
		score = 75
		quality = 75
		tags = "FILE"

	strings:
		$s1 = "shellx.pif" fullword ascii nocase
		$s2 = "Beasty" fullword ascii
		$s3 = "* Boot:[" ascii
		$s4 = "^ Shut Down:[" ascii
		$s5 = "set cdaudio door" ascii
		$s6 = "This \"Portable Network Graphics\" image is not valid" wide
		$n1 = ".aol.com" ascii
		$n2 = "web.icq.com" ascii
		$n3 = "&fromemail=" fullword ascii
		$n4 = "&subject=" fullword ascii
		$n5 = "&Send=" fullword ascii
		$n6 = "POST /scripts/WWPMsg.dll HTTP/1.0" fullword ascii
		$n7 = "mirabilis.com" ascii

	condition:
		uint16( 0 ) == 0x5a4d and ( all of ( $s* ) or 5 of ( $n* ) or ( 3 of ( $s* ) and 3 of ( $n* ) ) )
}

Strings (13 patterns)

IdentifierTypeValueModifiers
$s1text"shellx.pif"fullword ascii nocase
$s2text"Beasty"fullword ascii
$s3text"* Boot:["ascii
$s4text"^ Shut Down:["ascii
$s5text"set cdaudio door"ascii
$s6text"This \"Portable Network Graphics\" image is not valid"wide
$n1text".aol.com"ascii
$n2text"web.icq.com"ascii
$n3text"&fromemail="fullword ascii
$n4text"&subject="fullword ascii
$n5text"&Send="fullword ascii
$n6text"POST /scripts/WWPMsg.dll HTTP/1.0"fullword ascii
$n7text"mirabilis.com"ascii

Condition

uint16( 0 ) == 0x5a4d and ( all of ( $s* ) or 5 of ( $n* ) or ( 3 of ( $s* ) and 3 of ( $n* ) ) )

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • All patterns in ( $s* ) must match.
  • At least 5 patterns in ( $n* ) must match.
  • At least 3 patterns in ( $s* ) must match.
  • At least 3 patterns in ( $n* ) 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: b271d53e-2693-5a93-825a-ef32f72a4b01

Tags:FILE