| ID | Technique | Tactic |
|---|---|---|
| T1649 | Steal or Forge Authentication Certificates | Credential Access |
Detection: Windows Steal Authentication Certificates CertUtil Backup
Description
The following analytic detects CertUtil.exe performing a backup of the Certificate Store. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on specific command-line executions involving CertUtil with backup parameters. This activity is significant because it may indicate an attempt to steal authentication certificates, which are critical for secure communications. If confirmed malicious, an attacker could use the stolen certificates to impersonate users, decrypt sensitive data, or gain unauthorized access to systems, leading to severe security breaches.
Search
1
2| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
3 WHERE `process_certutil` Processes.process IN ("*-backupdb *", "*-backup *")
4 BY Processes.action Processes.dest Processes.original_file_name
5 Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
6 Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
7 Processes.process Processes.process_exec Processes.process_guid
8 Processes.process_hash Processes.process_id Processes.process_integrity_level
9 Processes.process_name Processes.process_path Processes.user
10 Processes.user_id Processes.vendor_product
11
12| `drop_dm_object_name(Processes)`
13
14| `security_content_ctime(firstTime)`
15
16| `security_content_ctime(lastTime)`
17
18| `windows_steal_authentication_certificates_certutil_backup_filter`
Data Source
| Name | Platform | Sourcetype | Source |
|---|---|---|---|
| CrowdStrike ProcessRollup2 | Other | 'crowdstrike:events:sensor' |
'crowdstrike' |
| Sysmon EventID 1 |  Windows |
'XmlWinEventLog' |
'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational' |
| Windows Event Log Security 4688 | Windows |
'XmlWinEventLog' |
'XmlWinEventLog:Security' |
Macros Used
| Name | Value |
|---|---|
| security_content_summariesonly | summariesonly=summariesonly_config allow_old_summaries=oldsummaries_config fillnull_value=fillnull_config`` |
| windows_steal_authentication_certificates_certutil_backup_filter | search * |
windows_steal_authentication_certificates_certutil_backup_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.AE
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 Finding (Notable) | No |
| Creates Intermediate Finding (Risk Event) | Yes |
Anomaly detections generate Intermediate Findings (Risk Events). They do not generate a Finding (Notable) directly.
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
False positives will be generated based on normal certificate store backups. Leave enabled to generate Risk, as this is meant to be an anomaly analytic. If CS backups are not normal, enable as TTP.
Associated Analytic Story
Intermediate Findings
| Message | Entity Field | Entity Type | Risk Score |
|---|---|---|---|
| An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ attempting to backup the Certificate Store. | user | user | 20 |
| An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ attempting to backup the Certificate Store. | dest | system | 20 |
Threat Objects
| Field | Type |
|---|---|
| process_name | process_name |
| parent_process_name | parent_process_name |
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: 13