Suspicious Kerberos Ticket Request via PowerShell Script - ScriptBlock

testhigh
log source: windows · ps_scriptauthor frack113date 2021-12-28
01

description

What this is, in brief.

Detects PowerShell scripts that utilize native PowerShell Identity modules to request Kerberos tickets. This behavior is typically seen during a Kerberoasting or silver ticket attack. A TGS request is issued by the KerberosRequestorSecurityToken constructor, resulting tickets are cached in LSA and become extractable by other tools later on.

02

tags

attack.credential-accessattack.t1558.003
03

rule source (YAML)

title: Suspicious Kerberos Ticket Request via PowerShell Script - ScriptBlock
id: a861d835-af37-4930-bcd6-5b178bfb54df
related:
    - id: caa9a802-8bd8-4b9e-a5cd-4d6221670219
      type: similar
status: test
description: |
    Detects PowerShell scripts that utilize native PowerShell Identity modules to request Kerberos tickets.
    This behavior is typically seen during a Kerberoasting or silver ticket attack. A TGS request is issued by
    the KerberosRequestorSecurityToken constructor, resulting tickets are cached in LSA and become
    extractable by other tools later on.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1558.003/T1558.003.md#atomic-test-4---request-a-single-ticket-via-powershell
    - https://learn.microsoft.com/en-us/dotnet/api/system.identitymodel.tokens.kerberosrequestorsecuritytoken?view=netframework-4.8.1
author: frack113
date: 2021-12-28
modified: 2026-09-14
tags:
    - attack.credential-access
    - attack.t1558.003
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection:
        ScriptBlockText|contains: 'System.IdentityModel.Tokens.KerberosRequestorSecurityToken'
    condition: selection
falsepositives:
    - Legitimate Kerberos authentication development and troubleshooting scripts
level: high
regression_tests_path: regression_data/rules/windows/powershell/powershell_script/posh_ps_request_kerberos_ticket/info.yml
04

detects techniques (1)

ATT&CK techniques this enables or maps to.

05

references

External citations — patches, advisories, analysis.