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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_HKTL_EXPL_WIN_PS1_Badsuccessor_May25

Detects PowerShell tool called Get-BadSuccessorOUPermissions.ps1 that helps exploit a vulnerability in Active Directory. Lists every principal that can perform a BadSuccessor attack and the OUs where it holds the required permissions.

Hack toolSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Florian Roth
Date
2025-05-22
Modified
2026-05-15
Score / Quality
75 / 85

What this rule detects

Detects PowerShell tool called Get-BadSuccessorOUPermissions.ps1 that helps exploit a vulnerability in Active Directory. Lists every principal that can perform a BadSuccessor attack and the OUs where it holds the required permissions.

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

Summary generated from the rule's metadata and condition.

Rule source

hktl-expl-win-ps1-badsuccessor-may25.yarDetection Rule License 1.1
rule SIGNATURE_BASE_HKTL_EXPL_WIN_PS1_Badsuccessor_May25 : FILE
{
	meta:
		description = "Detects PowerShell tool called Get-BadSuccessorOUPermissions.ps1 that helps exploit a vulnerability in Active Directory. Lists every principal that can perform a BadSuccessor attack and the OUs where it holds the required permissions."
		author = "Florian Roth"
		id = "4f6ff5ff-831a-520c-8bc5-6fec5e65f9de"
		date = "2025-05-22"
		modified = "2026-05-15"
		reference = "https://www.akamai.com/blog/security-research/abusing-dmsa-for-privilege-escalation-in-active-directory"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/hktl_badsuccessor_helper_may25.yar#L2-L16"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "a023bced4aec2b2c601088367766f42a3fcf36053c7eb92985cc7468c7cd6cb0"
		score = 75
		quality = 85
		tags = "FILE"

	strings:
		$x1 = "function Get-BadSuccessorOUPermissions" ascii wide
		$x2 = "\"0feb936f-47b3-49f2-9386-1dedc2c23765\"=\"msDS-DelegatedManagedServiceAccount\"" ascii wide
		$x3 = "CreateChild|GenericAll|WriteDACL|WriteOwner" ascii wide

	condition:
		filesize < 20MB and 1 of them
}

Strings (3 patterns)

IdentifierTypeValueModifiers
$x1text"function Get-BadSuccessorOUPermissions"ascii wide
$x2text"\"0feb936f-47b3-49f2-9386-1dedc2c23765\"=\"msDS-DelegatedManagedServiceAccount\""ascii wide
$x3text"CreateChild|GenericAll|WriteDACL|WriteOwner"ascii wide

Condition

filesize < 20MB and 1 of them

In plain words (Heuristic)

  • The file must be smaller than 20MB (a cheap guard that skips large files).
  • At least 1 patterns in the rule must match.

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References

Licence & attribution

Author: Florian Roth

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: 4f6ff5ff-831a-520c-8bc5-6fec5e65f9de

Tags:FILE