Detection: Windows Gather Victim Identity SAM Info

Updated Date: 2024-05-10 ID: a18e85d7-8b98-4399-820c-d46a1ca3516f Author: Teoderick Contreras, Splunk Type: Hunting Product: Splunk Enterprise Security

Description

The following analytic detects processes loading the samlib.dll or samcli.dll modules, which are often abused to access Security Account Manager (SAM) objects or credentials on domain controllers. This detection leverages Sysmon EventCode 7 to identify these DLLs being loaded outside typical system directories. Monitoring this activity is crucial as it may indicate attempts to gather sensitive identity information. If confirmed malicious, this behavior could allow attackers to obtain credentials, escalate privileges, or further infiltrate the network.

Search

1`sysmon` EventCode=7  (ImageLoaded = "*\\samlib.dll" AND OriginalFileName = "samlib.dll") OR (ImageLoaded = "*\\samcli.dll" AND OriginalFileName = "SAMCLI.DLL") AND NOT (Image IN("C:\\Windows\\*", "C:\\Program File*", "%systemroot%\\*")) 
2| stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded process_name dest EventCode Signed ProcessId 
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `windows_gather_victim_identity_sam_info_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_gather_victim_identity_sam_info_filter	`search *`

windows_gather_victim_identity_sam_info_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

ID	Technique	Tactic
T1589.001	Credentials	Reconnaissance
T1589	Gather Victim Identity Information	Reconnaissance

KillChainPhase.RECONNAISSANCE

NistCategory.DE_AE

Cis18Value.CIS_10

APT28

APT41

Chimera

LAPSUS$

Leviathan

Magic Hound

APT32

FIN13

HEXANE

LAPSUS$

Magic Hound

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 Risk Event	False

This configuration file applies to all detections of type hunting.

Implementation

The latest Sysmon TA 3.0 https://splunkbase.splunk.com/app/5709 will add the ImageLoaded name to the process_name field, allowing this query to work. Use as an example and implement for other products.

Known False Positives

this module can be loaded by a third party application. Filter is needed.

Associated Analytic Story

Brute Ratel C4

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
An instance of $dest$ that loads $ImageLoaded$ that are related to accessing to SAM object information.	9	30	30

The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

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: 2