Detection: Windows Drivers Loaded by Signature

Updated Date: 2024-05-10 ID: d2d4af6a-6c2b-4d79-80c5-fc2cf12a2f68 Author: Michael Haag, Splunk Type: Hunting Product: Splunk Enterprise Security

Description

The following analytic identifies all drivers being loaded on Windows systems using Sysmon EventCode 6 (Driver Load). It leverages fields such as driver path, signature status, and hash to detect potentially suspicious drivers. This activity is significant for a SOC as malicious drivers can be used to gain kernel-level access, bypass security controls, or persist in the environment. If confirmed malicious, this activity could allow an attacker to execute arbitrary code with high privileges, leading to severe system compromise and potential data exfiltration.

Search

1`sysmon` EventCode=6 
2| stats min(_time) as firstTime max(_time) as lastTime values(ImageLoaded) count by dest Signed Signature service_signature_verified service_signature_exists Hashes 
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `windows_drivers_loaded_by_signature_filter`

Data Source

Name	Platform	Sourcetype	Source	Supported App
Sysmon EventID 6	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_drivers_loaded_by_signature_filter	`search *`

windows_drivers_loaded_by_signature_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
T1014	Rootkit	Defense Evasion
T1068	Exploitation for Privilege Escalation	Privilege Escalation

KillChainPhase.EXPLOITAITON

NistCategory.DE_AE

Cis18Value.CIS_10

APT28

APT41

Rocke

TeamTNT

Winnti Group

APT28

APT29

APT32

APT33

BITTER

Cobalt Group

FIN6

FIN8

LAPSUS$

MoustachedBouncer

PLATINUM

Scattered Spider

Threat Group-3390

Tonto Team

Turla

Whitefly

ZIRCONIUM

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 Risk Event	False

This configuration file applies to all detections of type hunting.

Implementation

To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you must have the latest version of the Sysmon TA. Most EDR products provide the ability to review driver loads, or module loads, and using a query as such help with hunting for malicious drivers.

Known False Positives

This analytic is meant to assist with identifying drivers loaded in the environment and not to be setup for notables off the bat.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
A driver has loaded on $dest$.	42	60	70

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