Detection: Windows Modify Registry Qakbot Binary Data Registry

Description

The following analytic detects the creation of a suspicious registry entry by Qakbot malware, characterized by 8 random registry value names with encrypted binary data. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on registry modifications under the "SOFTWARE\Microsoft\" path by processes like explorer.exe. This activity is significant as it indicates potential Qakbot infection, which uses the registry to store malicious code or configuration data. If confirmed malicious, this could allow attackers to maintain persistence and execute arbitrary code on the compromised system.

Search

 1
 2| tstats `security_content_summariesonly` count dc(registry_value_name) as registry_value_name_count FROM datamodel=Endpoint.Registry where Registry.registry_path="*\\SOFTWARE\\Microsoft\\*" AND Registry.registry_value_data = "Binary Data" by _time span=1m Registry.dest Registry.user Registry.registry_path Registry.registry_value_name Registry.registry_value_data Registry.process_guid Registry.process_id Registry.registry_key_name 
 3| `drop_dm_object_name(Registry)` 
 4| eval registry_key_name_len = len(registry_key_name) 
 5| eval registry_value_name_len = len(registry_value_name) 
 6| regex registry_value_name="^[0-9a-fA-F]{8}" 
 7| where registry_key_name_len < 80 AND registry_value_name_len == 8 
 8| join process_guid, _time [
 9| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes where Processes.process_name IN ("explorer.exe", "wermgr.exe","dxdiag.exe", "OneDriveSetup.exe", "mobsync.exe", "msra.exe", "xwizard.exe") by _time span=1m Processes.process_id Processes.process_name Processes.process Processes.dest Processes.parent_process_name Processes.parent_process Processes.process_guid Processes.process_path 
10| `drop_dm_object_name(Processes)` ] 
11| stats min(_time) as firstTime max(_time) as lastTime values(registry_value_name) as registry_value_name dc(registry_value_name) as registry_value_name_count values(registry_key_name) by dest process_guid process_name parent_process_name 
12| `security_content_ctime(firstTime)` 
13| `security_content_ctime(lastTime)` 
14| where registry_value_name_count >= 5 
15| `windows_modify_registry_qakbot_binary_data_registry_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 1	Windows	'xmlwineventlog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'
Sysmon EventID 12	Windows	'xmlwineventlog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'
Sysmon EventID 13	Windows	'xmlwineventlog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'

Macros Used

Annotations

Default Configuration

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

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

unknown

Associated Analytic Story

• Qakbot

Risk Based Analytics (RBA)

References

• https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/decrypting-qakbots-encrypted-registry-keys/

Detection Testing

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: 4