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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_HKTL_NET_GUID_Fenrir

Detects c# red/black-team tools via typelibguid

Hack toolSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Arnim Rupp (https://github.com/ruppde)
Date
2020-12-13
Modified
2025-08-15
Score / Quality
75 / 85

What this rule detects

Detects c# red/black-team tools via typelibguid

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
hktl-net-guid-fenrir.yarDetection Rule License 1.1
rule SIGNATURE_BASE_HKTL_NET_GUID_Fenrir : FILE
{
	meta:
		description = "Detects c# red/black-team tools via typelibguid"
		author = "Arnim Rupp (https://github.com/ruppde)"
		id = "cfc6312d-5997-5261-b771-c7f3f30bf86c"
		date = "2020-12-13"
		modified = "2025-08-15"
		reference = "https://github.com/nccgroup/Fenrir"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/gen_github_net_redteam_tools_guids.yar#L1470-L1483"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "9b62914aea33db4027c62ecf57854d20942197d1b9212245d1932c0a6b80fe5f"
		score = 75
		quality = 85
		tags = "FILE"
		license = "Detection Rule License 1.1 https://github.com/Neo23x0/signature-base/blob/master/LICENSE"

	strings:
		$typelibguid0lo = "aecec195-f143-4d02-b946-df0e1433bd2e" ascii wide

	condition:
		( uint16( 0 ) == 0x5A4D and uint32( uint32( 0x3C ) ) == 0x00004550 ) and any of them
}

Strings (1 patterns)

IdentifierTypeValueModifiers
$typelibguid0lotext"aecec195-f143-4d02-b946-df0e1433bd2e"ascii wide

Condition

( uint16( 0 ) == 0x5A4D and uint32( uint32( 0x3C ) ) == 0x00004550 ) and any of them

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • At least one pattern in the rule must match.

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References

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/Neo23x0/signature-base/blob/master/LICENSE”

Original rule

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

Rule id: cfc6312d-5997-5261-b771-c7f3f30bf86c

Tags:FILE

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