| ID | Technique | Tactic |
|---|---|---|
| T1112 | Modify Registry | Defense Evasion |
Detection: Revil Registry Entry
Description
The following analytic identifies suspicious modifications in the registry entry, specifically targeting paths used by malware like REVIL. It detects changes in registry paths such as SOFTWARE\\WOW6432Node\\Facebook_Assistant and SOFTWARE\\WOW6432Node\\BlackLivesMatter. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on registry modifications linked to process GUIDs. This activity is significant as it indicates potential malware persistence mechanisms, often used by advanced persistent threats (APTs) and ransomware. If confirmed malicious, this could allow attackers to maintain persistence, encrypt files, and store critical ransomware-related information on compromised hosts.
Search
1
2| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry WHERE (Registry.registry_path="*\\SOFTWARE\\WOW6432Node\\Facebook_Assistant\\*" OR Registry.registry_path="*\\SOFTWARE\\WOW6432Node\\BlackLivesMatter*") by Registry.action Registry.dest Registry.process_guid Registry.process_id Registry.registry_hive Registry.registry_path Registry.registry_key_name Registry.registry_value_data Registry.registry_value_name Registry.registry_value_type Registry.status Registry.user Registry.vendor_product
3| `drop_dm_object_name(Registry)`
4| `security_content_ctime(firstTime)`
5| `security_content_ctime(lastTime)`
6| `revil_registry_entry_filter`
Data Source
| Name | Platform | Sourcetype | Source |
|---|---|---|---|
| Sysmon EventID 12 |  Windows |
'xmlwineventlog' |
'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational' |
| Sysmon EventID 13 | Windows |
'xmlwineventlog' |
'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational' |
Macros Used
| Name | Value |
|---|---|
| security_content_ctime | convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$) |
| revil_registry_entry_filter | search * |
revil_registry_entry_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
Exploitation
DE.CM
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
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
Risk Based Analytics (RBA)
Risk Message:
A registry entry $registry_path$ with registry value $registry_value_name$ and $registry_value_name$ related to revil ransomware in host $dest$
| Risk Object | Risk Object Type | Risk Score | Threat Objects |
|---|---|---|---|
| dest | system | 60 | No Threat Objects |
| user | user | 60 | 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: 7