Detection: Creation of lsass Dump with Taskmgr

Updated Date: 2024-09-30 ID: b2fbe95a-9c62-4c12-8a29-24b97e84c0cd Author: Michael Haag, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the creation of an lsass.exe process dump using Windows Task Manager. It leverages Sysmon EventID 11 to identify file creation events where the target filename matches lsass.dmp. This activity is significant because creating an lsass dump can be a precursor to credential theft, as the dump file contains sensitive information such as user passwords. If confirmed malicious, an attacker could use the lsass dump to extract credentials and escalate privileges, potentially compromising the entire network.

Search

1`sysmon` EventID=11 process_name=taskmgr.exe TargetFilename=*lsass*.dmp 
2| stats count min(_time) as firstTime max(_time) as lastTime by dest, object_category, process_name, TargetFilename  
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `creation_of_lsass_dump_with_taskmgr_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 11	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
creation_of_lsass_dump_with_taskmgr_filter	`search *`

creation_of_lsass_dump_with_taskmgr_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
T1003.001	LSASS Memory	Credential Access
T1003	OS Credential Dumping	Credential Access

KillChainPhase.EXPLOITAITON

NistCategory.DE_CM

Cis18Value.CIS_10

APT1

APT28

APT3

APT32

APT33

APT39

APT41

APT5

Agrius

Aquatic Panda

BRONZE BUTLER

Blue Mockingbird

Cleaver

Earth Lusca

Ember Bear

FIN13

FIN6

FIN8

Fox Kitten

GALLIUM

HAFNIUM

Indrik Spider

Ke3chang

Kimsuky

Leafminer

Leviathan

Magic Hound

Moonstone Sleet

MuddyWater

OilRig

PLATINUM

Play

RedCurl

Sandworm Team

Silence

Threat Group-3390

Volt Typhoon

Whitefly

Wizard Spider

APT28

APT32

APT39

Axiom

Ember Bear

Leviathan

Poseidon Group

Sowbug

Suckfly

Tonto Team

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

This search requires Sysmon Logs and a Sysmon configuration, which includes EventCode 11 for detecting file create of lsass.dmp. This search uses an input macro named sysmon. We strongly recommend that you specify your environment-specific configurations (index, source, sourcetype, etc.) for Windows Sysmon logs. Replace the macro definition with configurations for your Splunk environment. The search also uses a post-filter macro designed to filter out known false positives.

Known False Positives

Administrators can create memory dumps for debugging purposes, but memory dumps of the LSASS process would be unusual.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
$process_name$ was identified on endpoint $dest$ writing $TargetFilename$ to disk. This behavior is related to dumping credentials via Task Manager.	80	80	100

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: 3