Detection: Windows System Discovery Using ldap Nslookup

Updated Date: 2024-05-28 ID: 2418780f-7c3e-4c45-b8b4-996ea850cd49 Author: Teoderick Contreras, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic detects the execution of nslookup.exe to query domain information using LDAP. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line arguments. This activity is significant as nslookup.exe can be abused by malware like Qakbot to gather critical domain details, such as SRV records and server names. If confirmed malicious, this behavior could allow attackers to map the network, identify key servers, and plan further attacks, potentially leading to data exfiltration or lateral movement within the network.

Search

1
2| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process_name = "nslookup.exe" OR Processes.original_file_name = "nslookup.exe") AND Processes.process = "*_ldap._tcp.dc._msdcs*" by Processes.parent_process Processes.parent_process_name Processes.process_name Processes.process_id Processes.process_guid Processes.process Processes.user Processes.dest Processes.parent_process_id Processes.original_file_name 
3| `drop_dm_object_name("Processes")` 
4| `security_content_ctime(firstTime)` 
5|`security_content_ctime(lastTime)` 
6| `windows_system_discovery_using_ldap_nslookup_filter`

Data Source

Name	Platform	Sourcetype	Source	Supported App
CrowdStrike ProcessRollup2	N/A	`'crowdstrike:events:sensor'`	`'crowdstrike'`	N/A

Macros Used

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

windows_system_discovery_using_ldap_nslookup_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
T1033	System Owner/User Discovery	Discovery

KillChainPhase.EXPLOITAITON

NistCategory.DE_AE

Cis18Value.CIS_10

APT19

APT3

APT32

APT37

APT38

APT39

APT41

Chimera

Dragonfly

Earth Lusca

FIN10

FIN7

FIN8

GALLIUM

Gamaredon Group

HAFNIUM

HEXANE

Ke3chang

Lazarus Group

LuminousMoth

Magic Hound

MuddyWater

OilRig

Patchwork

Sandworm Team

Sidewinder

Stealth Falcon

Threat Group-3390

Tropic Trooper

Volt Typhoon

Windshift

Wizard Spider

ZIRCONIUM

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	True

This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

dministrator may execute this commandline tool for auditing purposes. Filter as needed.

Associated Analytic Story

Qakbot

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
System nslookup domain discovery on $dest$	1	10	10

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