Windows Registry SIP Persistence via New Cryptography Provider Registration

Detects suspicious Windows registry writes that register a new SIP/Cryptography provider DLL for persistence or defense impairment.

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windows-registry-sip-persistence-via-new-cryptography-provider-registration-5a2b21ee

title: Windows Registry SIP Persistence via New Cryptography Provider Registration
id: 59939c0d-1af0-44e0-8c9b-5018005d209d
status: test
description: This rule flags registry activity consistent with registering or updating a Security Information Provider (SIP) by targeting Cryptography provider and EncodingType keys. Attackers may use SIP changes to influence trust decisions or impede defense mechanisms by persisting malicious trust-related configuration. It relies on Windows registry set telemetry matching specific provider-related registry paths and SIP-related DLL string patterns, while excluding known legitimate provider details and suppressing events involving poqexec and CryptSIPDll.
references:
  - https://persistence-info.github.io/Data/codesigning.html
  - https://github.com/gtworek/PSBits/tree/master/SIP
  - https://specterops.io/assets/resources/SpecterOps_Subverting_Trust_in_Windows.pdf
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/registry/registry_set/registry_set_sip_persistence.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2022-07-21
modified: 2023-08-17
tags:
  - attack.persistence
  - attack.defense-impairment
  - attack.t1553.003
logsource:
  category: registry_set
  product: windows
detection:
  selection_root:
    TargetObject|contains:
      - \SOFTWARE\Microsoft\Cryptography\Providers\
      - \SOFTWARE\Microsoft\Cryptography\OID\EncodingType
      - \SOFTWARE\WOW6432Node\Microsoft\Cryptography\Providers\
      - \SOFTWARE\WOW6432Node\Microsoft\Cryptography\OID\EncodingType
  selection_dll:
    TargetObject|contains:
      - \Dll
      - \$DLL
  filter:
    Details:
      - WINTRUST.DLL
      - mso.dll
  filter_poqexec:
    Image: C:\Windows\System32\poqexec.exe
    TargetObject|contains: \CryptSIPDll
    Details: C:\Windows\System32\PsfSip.dll
  condition: all of selection_* and not 1 of filter*
falsepositives:
  - Legitimate SIP being registered by the OS or different software.
level: medium
license: DRL-1.1
related:
  - id: 5a2b21ee-6aaa-4234-ac9d-59a59edf90a1
    type: derived

What it detects

This rule flags registry activity consistent with registering or updating a Security Information Provider (SIP) by targeting Cryptography provider and EncodingType keys. Attackers may use SIP changes to influence trust decisions or impede defense mechanisms by persisting malicious trust-related configuration. It relies on Windows registry set telemetry matching specific provider-related registry paths and SIP-related DLL string patterns, while excluding known legitimate provider details and suppressing events involving poqexec and CryptSIPDll.

Known false positives

Legitimate SIP being registered by the OS or different software.

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.