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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_MAL_RANSOM_Darkside_May21_1

Detects Darkside Ransomware

MalwareDarkSideSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Florian Roth (Nextron Systems)
Date
2021-05-10
Modified
2023-12-05
Score / Quality
75 / 85

What this rule detects

Detects Darkside Ransomware

Associated malware family: DarkSide.

Targets: Windows PE.

It defines 7 patterns (3 text, 4 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
mal-ransom-darkside-may21-1.yarDetection Rule License 1.1
rule SIGNATURE_BASE_MAL_RANSOM_Darkside_May21_1 : FILE
{
	meta:
		description = "Detects Darkside Ransomware"
		author = "Florian Roth (Nextron Systems)"
		id = "e5592065-591e-597b-bebb-f20bc306fe52"
		date = "2021-05-10"
		modified = "2023-12-05"
		reference = "https://app.any.run/tasks/020c1740-717a-4191-8917-5819aa25f385/"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/crime_ransom_darkside.yar#L2-L23"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		hash = "ec368752c2cf3b23efbfa5705f9e582fc9d6766435a7b8eea8ef045082c6fbce"
		logic_hash = "84de92b0b36e373aa61e314a04597bd0578a04af34c501ae9071e5f4fa27c07a"
		score = 75
		quality = 85
		tags = "FILE"

	strings:
		$op1 = { 85 c9 75 ed ff 75 10 ff b5 d8 fe ff ff ff b5 dc fe ff ff e8 7d fc ff ff ff 8d cc fe ff ff 8b 8d cc fe ff ff }
		$op2 = { 66 0f 6f 06 66 0f 7f 07 83 c6 10 83 c7 10 49 85 c9 75 ed 5f }
		$op3 = { 6a 00 ff 15 72 0d 41 00 ab 46 81 fe 80 00 00 00 75 2e 6a ff 6a 01 }
		$op4 = { 0f b7 0c 5d 88 0f 41 00 03 4c 24 04 89 4c 24 04 83 e1 3f 0f b7 14 4d 88 0f 41 00 03 54 24 08 89 54 24 08 83 e2 3f }
		$s1 = "http://darksid" ascii
		$s2 = "[ Welcome to DarkSide ]" ascii
		$s3 = ".onion/" ascii

	condition:
		uint16( 0 ) == 0x5a4d and filesize < 200KB and 3 of them or all of ( $op* ) or all of ( $s* )
}

Strings (7 patterns)

IdentifierTypeValueModifiers
$op1hex{ 85 c9 75 ed ff 75 10 ff b5 d8 fe ff ff ff b5 dc fe ff ff e8 7d fc ff ff ff 8d cc fe ff ff 8b 8d cc fe ff ff }
$op2hex{ 66 0f 6f 06 66 0f 7f 07 83 c6 10 83 c7 10 49 85 c9 75 ed 5f }
$op3hex{ 6a 00 ff 15 72 0d 41 00 ab 46 81 fe 80 00 00 00 75 2e 6a ff 6a 01 }
$op4hex{ 0f b7 0c 5d 88 0f 41 00 03 4c 24 04 89 4c 24 04 83 e1 3f 0f b7 14 4d 88 0f 41 00 03 54 24 08 89 54 24 08 83 e2 3f }
$s1text"http://darksid"ascii
$s2text"[ Welcome to DarkSide ]"ascii
$s3text".onion/"ascii

Condition

uint16( 0 ) == 0x5a4d and filesize < 200KB and 3 of them or all of ( $op* ) or all of ( $s* )

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • The file must be smaller than 200KB (a cheap guard that skips large files).
  • All patterns in ( $op* ) must match.
  • All patterns in ( $s* ) must match.
  • At least 3 patterns in the rule must match.

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References

Sample hashes

Hashes of samples the author lists in the rule's meta (look them up in your threat-intelligence platform).

  • ec368752c2cf3b23efbfa5705f9e582fc9d6766435a7b8eea8ef045082c6fbce

Licence & attribution

Author: Florian Roth (Nextron Systems)

Source repository: Signature Base (Florian Roth / Nextron) @ 94a1c48d7a

Licence: Detection Rule License 1.1 (repository licence)

Original rule

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

Rule id: e5592065-591e-597b-bebb-f20bc306fe52

Tags:FILE

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