Detection: Create Remote Thread into LSASS

Updated Date: 2024-08-14 ID: 67d4dbef-9564-4699-8da8-03a151529edc Author: Patrick Bareiss, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the creation of a remote thread in the Local Security Authority Subsystem Service (LSASS). This behavior is identified using Sysmon Event ID 8 logs, focusing on processes that create remote threads in lsass.exe. This activity is significant because it is commonly associated with credential dumping, a tactic used by adversaries to steal user authentication credentials. If confirmed malicious, this could allow attackers to gain unauthorized access to sensitive information, leading to potential compromise of the entire network. Analysts should investigate to differentiate between legitimate tools and potential threats.

Search

1`sysmon` EventID=8 TargetImage=*lsass.exe 
2| stats count min(_time) as firstTime max(_time) as lastTime by dest, EventCode, TargetImage, TargetProcessId 
3| `security_content_ctime(firstTime)`
4| `security_content_ctime(lastTime)` 
5| `create_remote_thread_into_lsass_filter`

Data Source

Name	Platform	Sourcetype	Source	Supported App
Sysmon EventID 8	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($field$)`
create_remote_thread_into_lsass_filter	`search *`

create_remote_thread_into_lsass_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

Aquatic Panda

BRONZE BUTLER

Blue Mockingbird

Cleaver

Earth Lusca

FIN13

FIN6

FIN8

Fox Kitten

GALLIUM

HAFNIUM

Indrik Spider

Ke3chang

Kimsuky

Leafminer

Leviathan

Magic Hound

MuddyWater

OilRig

PLATINUM

Sandworm Team

Silence

Threat Group-3390

Volt Typhoon

Whitefly

Wizard Spider

APT28

APT32

APT39

Axiom

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 needs Sysmon Logs with a Sysmon configuration, which includes EventCode 8 with lsass.exe. 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

Other tools can access LSASS for legitimate reasons and generate an event. In these cases, tweaking the search may help eliminate noise.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
A process has created a remote thread into $TargetImage$ on $dest$. This behavior is indicative of credential dumping and should be investigated.	81	90	90

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

https://2017.zeronights.org/wp-content/uploads/materials/ZN17_Kheirkhabarov_Hunting_for_Credentials_Dumping_in_Windows_Environment.pdf

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