Detection: Windows Registry SIP Provider Modification

Updated Date: 2024-05-28 ID: 3b4e18cb-497f-4073-85ad-1ada7c2107ab Author: Michael Haag, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects modifications to the Windows Registry SIP Provider. It leverages Sysmon EventID 7 to monitor registry changes in paths and values related to Cryptography Providers and OID Encoding Types. This activity is significant as it may indicate an attempt to subvert trust controls, a common tactic for bypassing security measures and maintaining persistence. If confirmed malicious, an attacker could manipulate the system's cryptographic functions, potentially leading to unauthorized access, data theft, or other damaging outcomes. Review the modified registry paths and concurrent processes to identify the attack source.

Search

1
2| tstats `security_content_summariesonly` count values(Registry.registry_key_name) as registry_key_name values(Registry.registry_path) as registry_path min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Registry where Registry.registry_path IN ("*\\SOFTWARE\\Microsoft\\Cryptography\\Providers\\*", "*\\SOFTWARE\\Microsoft\\Cryptography\\OID\\EncodingType*", "*\\SOFTWARE\\WOW6432Node\\Microsoft\\Cryptography\\Providers\\*", "*\\SOFTWARE\\WOW6432Node\\Microsoft\\Cryptography\\OID\\EncodingType*") Registry.registry_value_name IN ("Dll","$DLL") by Registry.dest , Registry.user Registry.registry_value_name, Registry.registry_value_data 
3| `security_content_ctime(lastTime)` 
4| `security_content_ctime(firstTime)` 
5| `drop_dm_object_name(Registry)`
6| `windows_registry_sip_provider_modification_filter`

Data Source

Name	Platform	Sourcetype	Source	Supported App
Sysmon EventID 12	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`	N/A

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
windows_registry_sip_provider_modification_filter	`search *`

windows_registry_sip_provider_modification_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1553.003	SIP and Trust Provider Hijacking	Defense Evasion

KillChainPhase.EXPLOITAITON

NistCategory.DE_CM

Cis18Value.CIS_10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Notable	Yes
Rule Title	`%name%`
Rule Description	`%description%`
Notable Event Fields	user, dest
Creates Risk Event	True

This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the Endpoint datamodel in the Registry node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.

Known False Positives

Be aware of potential false positives - legitimate applications may cause benign activities to be flagged.

Associated Analytic Story

Subvert Trust Controls SIP and Trust Provider Hijacking

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
Windows Registry SIP Provider Modification detected on $dest$.	64	80	80

The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`xmlwineventlog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`xmlwineventlog`

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 2