Detection: Windows Suspicious QEMU Execution

Description

Detects execution of the QEMU binary and an image file with the -nographic flag. This causes it to run in the background without any display. This has been observed as a persistence and initial access technique by some threat actors to install a rogue linux virtual machine

 1`sysmon`
 2EventID=1
 3CommandLine="*-nographic*"
 4CommandLine="*.img*"
 5(
 6    Description="*QEMU machine*"
 7    OR
 8    Product="QEMU"
 9    OR
10    Company="*qemu*"
11)
12
13| fillnull
14
15| stats count min(_time) as firstTime
16              max(_time) as lastTime
17  by Computer EventID CommandLine Description Product Company action dest
18     original_file_name parent_process parent_process_exec parent_process_guid
19     parent_process_id parent_process_name parent_process_path process_hash
20     process_integrity_level user user_id vendor_product
21
22
23| `security_content_ctime(firstTime)`
24
25| `security_content_ctime(lastTime)`
26
27| `windows_suspicious_qemu_execution_filter`

Data Source

Name Platform Sourcetype Source
Sysmon EventID 1 Windows icon Windows 'XmlWinEventLog' 'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
windows_suspicious_qemu_execution_filter search *
windows_suspicious_qemu_execution_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

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

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

Some legitimate virtual machine setups or automated testing environments may run QEMU with the -nographic flag. Review and whitelist approved systems to reduce false alerts.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

Potential suspicious QEMU execution observed on $dest$ via $CommandLine$.

Risk Object Risk Object Type Risk Score Threat Objects
dest system 50 No Threat Objects

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: 1