Detection: Windows LOLBAS Executed Outside Expected Path

Updated Date: 2024-04-29 ID: 326fdf44-b90c-4d2e-adca-1fd140b10536 Author: Steven Dick Type: TTP Product: Splunk Enterprise Security

Description

The following analytic identifies a LOLBAS process being executed outside of it's expected location. Processes being executed outside of expected locations may be an indicator that an adversary is attempting to evade defenses or execute malicious code. The LOLBAS project documents Windows native binaries that can be abused by threat actors to perform tasks like executing malicious code.

Search

1
2|  tstats `security_content_summariesonly` latest(Processes.parent_process) as parent_process, latest(Processes.process) as process, latest(Processes.process_guid) as process_guid count, min(_time) AS firstTime, max(_time) AS lastTime FROM datamodel=Endpoint.Processes where Processes.process != "unknown" AND NOT Processes.process_path IN ("*\\Program Files*","*\\PROGRA~*","*\\Windows\\System32\\*","*\\Windows\\Syswow64\\*") BY Processes.user Processes.dest Processes.parent_process_name Processes.process_name Processes.process_path 
3|`drop_dm_object_name(Processes)` 
4| lookup lolbas_file_path lolbas_file_name as process_name OUTPUT description as desc 
5| lookup lolbas_file_path lolbas_file_name as process_name lolbas_file_path as process_path OUTPUT description as is_lolbas_path 
6| search desc!="false" AND is_lolbas_path="false" 
7| `security_content_ctime(firstTime)` 
8| `security_content_ctime(lastTime)` 
9| `windows_lolbas_executed_outside_expected_path_filter`

Data Source

Name	Platform	Sourcetype	Source	Supported App
Sysmon EventID 1	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_lolbas_executed_outside_expected_path_filter	`search *`

windows_lolbas_executed_outside_expected_path_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
T1036	Masquerading	Defense Evasion
T1036.005	Match Legitimate Name or Location	Defense Evasion
T1218.011	Rundll32	Defense Evasion

KillChainPhase.EXPLOITAITON

NistCategory.DE_CM

Cis18Value.CIS_10

APT28

APT32

BRONZE BUTLER

Dragonfly

FIN13

LazyScripter

Nomadic Octopus

OilRig

PLATINUM

Sandworm Team

TA551

TeamTNT

Windshift

ZIRCONIUM

menuPass

APT1

APT28

APT29

APT32

APT39

APT41

APT5

Aoqin Dragon

BRONZE BUTLER

BackdoorDiplomacy

Blue Mockingbird

Carbanak

Chimera

Darkhotel

Earth Lusca

FIN13

FIN7

Ferocious Kitten

Fox Kitten

Gamaredon Group

Indrik Spider

Ke3chang

Kimsuky

Lazarus Group

LuminousMoth

Machete

Magic Hound

MuddyWater

Mustang Panda

Mustard Tempest

Naikon

PROMETHIUM

Patchwork

Poseidon Group

Rocke

Sandworm Team

SideCopy

Sidewinder

Silence

Sowbug

TA2541

TeamTNT

ToddyCat

Transparent Tribe

Tropic Trooper

Volt Typhoon

WIRTE

Whitefly

admin@338

menuPass

APT19

APT28

APT3

APT32

APT38

APT41

Blue Mockingbird

Carbanak

CopyKittens

FIN7

Gamaredon Group

HAFNIUM

Kimsuky

Lazarus Group

LazyScripter

Magic Hound

MuddyWater

Sandworm Team

TA505

TA551

Wizard Spider

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

To implement this search, you must ingest logs that contain the process name and process path, such as with Sysmon EID 1.

Known False Positives

Vendors will often copy system exectables to a different path for application usage.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
The user $user$ executed a LOLBAS [$process_name$] from an unexpected location on $dest$	40	80	50

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: 1