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FIREEYE_RT_APT_Hacktool_MSIL_SHARPNFS_1

The TypeLibGUID present in a .NET binary maps directly to the ProjectGuid found in the '.csproj' file of a .NET project. This rule looks for .NET PE files that contain the ProjectGuid found in the 'sharpnfs' project.

APT / threat actorMandiant red team tool countermeasuresBSD 2-Clause LicenseCompiles with YARA-X
Author
FireEye
Date
2020-12-08
Modified
2020-12-09
Score / Quality
75 / 73

What this rule detects

The TypeLibGUID present in a .NET binary maps directly to the ProjectGuid found in the '.csproj' file of a .NET project. This rule looks for .NET PE files that contain the ProjectGuid found in the 'sharpnfs' project.

Targets: Windows PE.

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

Summary generated from the rule's metadata and condition.

Rule source

apt-hacktool-msil-sharpnfs-1.yarBSD 2-Clause License
rule FIREEYE_RT_APT_Hacktool_MSIL_SHARPNFS_1 : FILE
{
	meta:
		description = "The TypeLibGUID present in a .NET binary maps directly to the ProjectGuid found in the '.csproj' file of a .NET project. This rule looks for .NET PE files that contain the ProjectGuid found in the 'sharpnfs' project."
		author = "FireEye"
		id = "b9d1b4e8-644a-5611-85e8-a124f915b443"
		date = "2020-12-08"
		modified = "2020-12-09"
		reference = "https://github.com/mandiant/red_team_tool_countermeasures/"
		source_url = "https://github.com/mandiant/red_team_tool_countermeasures//blob/3561b71724dbfa3e2bb78106aaa2d7f8b892c43b/rules/UNCATEGORIZED/production/yara/APT_HackTool_MSIL_SHARPNFS_1.yar#L4-L15"
		license_url = "https://github.com/mandiant/red_team_tool_countermeasures//blob/3561b71724dbfa3e2bb78106aaa2d7f8b892c43b/LICENSE.txt"
		hash = "dd8805d0e470e59b829d98397507d8c2"
		logic_hash = "e7f9883376b153849970599d9ecc308882eb86a67834cfd8ab06b44539346125"
		score = 75
		quality = 73
		tags = "FILE"
		rev = 3

	strings:
		$typelibguid0 = "9f67ebe3-fc9b-40f2-8a18-5940cfed44cf" ascii nocase wide

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

Strings (1 patterns)

IdentifierTypeValueModifiers
$typelibguid0text"9f67ebe3-fc9b-40f2-8a18-5940cfed44cf"ascii nocase 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

Sample hashes

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

  • dd8805d0e470e59b829d98397507d8c2

Licence & attribution

Author: FireEye

Source repository: Mandiant red team tool countermeasures @ 3561b71724

Licence: BSD 2-Clause License (repository licence)

Copyright notice: Copyright (c) 2023, MANDIANT

Original rule

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

Rule id: b9d1b4e8-644a-5611-85e8-a124f915b443

Metadata

rev3

Tags:FILE