Persistence Via New SIP Provider

Hunt Hypothesis

Detects when an attacker register a new SIP provider for persistence and defense evasion

Detection Rule

Sigma (Original)

title: Persistence Via New SIP Provider
id: 5a2b21ee-6aaa-4234-ac9d-59a59edf90a1
status: test
description: Detects when an attacker register a new SIP provider for persistence and defense evasion
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
author: Nasreddine Bencherchali (Nextron Systems)
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:
            # Add more legitimate SIP providers according to your env
            - 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

KQL (Azure Sentinel)

imRegistry
| where ((RegistryKey endswith "\\SOFTWARE\\Microsoft\\Cryptography\\Providers*" or RegistryKey contains "\\SOFTWARE\\Microsoft\\Cryptography\\OID\\EncodingType" or RegistryKey endswith "\\SOFTWARE\\WOW6432Node\\Microsoft\\Cryptography\\Providers*" or RegistryKey contains "\\SOFTWARE\\WOW6432Node\\Microsoft\\Cryptography\\OID\\EncodingType") and (RegistryKey contains "\\Dll" or RegistryKey contains "\\$DLL")) and (not(((RegistryValueData in~ ("WINTRUST.DLL", "mso.dll")) or (ActingProcessName =~ "C:\\Windows\\System32\\poqexec.exe" and RegistryKey contains "\\CryptSIPDll" and RegistryValueData =~ "C:\\Windows\\System32\\PsfSip.dll"))))

Required Data Sources

False Positive Guidance

• Legitimate SIP being registered by the OS or different software.

MITRE ATT&CK Context

• Tactic: Persistence
• Technique: T1553.003 — T1553.003

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
• SigmaHQ Rule