ID | Technique | Tactic |
---|---|---|
T1218.004 | InstallUtil | Defense Evasion |
T1218 | System Binary Proxy Execution | Defense Evasion |
Detection: Windows InstallUtil Credential Theft
Description
The following analytic detects instances where the Windows InstallUtil.exe binary loads vaultcli.dll
and Samlib.dll
. This detection leverages Sysmon EventCode 7 to identify these specific DLL loads. This activity is significant because it can indicate an attempt to execute code that bypasses application control and captures credentials using tools like Mimikatz. If confirmed malicious, this behavior could allow an attacker to steal credentials, potentially leading to unauthorized access and further compromise of the system.
Search
1`sysmon` EventCode=7 process_name=installutil.exe loaded_file_path IN ("*\\samlib.dll", "*\\vaultcli.dll")
2| stats count min(_time) as firstTime max(_time) as lastTime by user_id, dest, process_name, loaded_file, loaded_file_path, original_file_name, process_guid
3| `security_content_ctime(firstTime)`
4| `security_content_ctime(lastTime)`
5| `windows_installutil_credential_theft_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
Sysmon EventID 7 | 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_installutil_credential_theft_filter | search * |
windows_installutil_credential_theft_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 |
Implementation
To successfully implement this search, you need to be ingesting logs with the process name, parent process, and module loads from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.
Known False Positives
Typically, this will not trigger because, by its very nature, InstallUtil does not require credentials. Filter as needed.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
An instance of process name [$process_name$] loading a file [$loaded_file$] was identified on endpoint- [$dest$] to potentially capture credentials in memory. | 80 | 80 | 100 |
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: 5