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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_MAL_Gopuram_Apr23

Detects Lazarus Gopuram malware

MalwareGopuramSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Arnim Rupp (https://github.com/ruppde)
Date
2023-04-04
Modified
2023-12-05
Score / Quality
75 / 85

What this rule detects

Detects Lazarus Gopuram malware

Associated malware family: Gopuram.

Targets: Windows PE.

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

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
mal-gopuram-apr23.yarDetection Rule License 1.1
rule SIGNATURE_BASE_MAL_Gopuram_Apr23 : FILE
{
	meta:
		description = "Detects Lazarus Gopuram malware"
		author = "Arnim Rupp (https://github.com/ruppde)"
		id = "e0bb43b0-542b-5c8e-bcba-0326f80efaa0"
		date = "2023-04-04"
		modified = "2023-12-05"
		reference = "https://securelist.com/gopuram-backdoor-deployed-through-3cx-supply-chain-attack/109344/"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/apt_lazarus_gopuram.yar#L1-L16"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		hash = "beb775af5196f30e0ee021790a4978ca7a7ac2a7cf970a5a620ffeb89cc60b2c"
		hash = "97b95b4a5461f950e712b82783930cb2a152ec0288c00a977983ca7788342df7"
		logic_hash = "58d978bd09a656f2a10a4d5d2585e51efe5cfb6b6648a4b3c2ce8c4f5d2256d4"
		score = 75
		quality = 85
		tags = "FILE"
		license = "Detection Rule License 1.1 https://github.com/SigmaHQ/Detection-Rule-License"

	strings:
		$path = "%s.TxR.0.regtrans-ms"

	condition:
		uint16( 0 ) == 0x5A4D and $path and filesize < 10MB
}

Strings (1 patterns)

IdentifierTypeValueModifiers
$pathtext"%s.TxR.0.regtrans-ms"

Condition

uint16( 0 ) == 0x5A4D and $path and filesize < 10MB

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • The file must be smaller than 10MB (a cheap guard that skips large files).
  • Pattern $path must be present.

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Drop a file here or click to chooseScanned locally with YARA-X. Files up to 200 MB.

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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).

  • beb775af5196f30e0ee021790a4978ca7a7ac2a7cf970a5a620ffeb89cc60b2c
  • 97b95b4a5461f950e712b82783930cb2a152ec0288c00a977983ca7788342df7

Licence & attribution

Author: Arnim Rupp (https://github.com/ruppde)

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

Licence: Detection Rule License 1.1 (stated in the rule's own meta)

“Detection Rule License 1.1 https://github.com/SigmaHQ/Detection-Rule-License”

Original rule

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

Rule id: e0bb43b0-542b-5c8e-bcba-0326f80efaa0

Tags:FILE

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