Detection: Windows MSIExec With Network Connections

Updated Date: 2024-09-30 ID: 827409a1-5393-4d8d-8da4-bbb297c262a7 Author: Michael Haag, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects MSIExec making network connections over ports 443 or 80. This behavior is identified by correlating process creation events from Endpoint Detection and Response (EDR) agents with network traffic logs. Typically, MSIExec does not perform network communication to the internet, making this activity unusual and potentially indicative of malicious behavior. If confirmed malicious, an attacker could be using MSIExec to download or communicate with external servers, potentially leading to data exfiltration, command and control (C2) communication, or further malware deployment.

Search

 1
 2| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes where `process_msiexec` by _time Processes.user Processes.process_id Processes.process_name Processes.dest Processes.process_path Processes.process Processes.parent_process_name 
 3| `drop_dm_object_name(Processes)` 
 4| `security_content_ctime(firstTime)` 
 5| `security_content_ctime(lastTime)` 
 6| join  process_id [
 7| tstats `security_content_summariesonly` count FROM datamodel=Network_Traffic.All_Traffic where All_Traffic.dest_port IN ("80","443") by All_Traffic.process_id All_Traffic.dest All_Traffic.dest_port All_Traffic.dest_ip 
 8| `drop_dm_object_name(All_Traffic)` ] 
 9| table _time user dest parent_process_name process_name process_path process process_id dest_port dest_ip 
10| `windows_msiexec_with_network_connections_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 1	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`
Sysmon EventID 3	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`

Macros Used

Name	Value
process_msiexec	`(Processes.process_name=msiexec.exe OR Processes.original_file_name=msiexec.exe)`
windows_msiexec_with_network_connections_filter	`search *`

windows_msiexec_with_network_connections_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
T1218.007	Msiexec	Defense Evasion

KillChainPhase.EXPLOITAITON

NistCategory.DE_CM

Cis18Value.CIS_10

Machete

Molerats

Rancor

TA505

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 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

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

False positives will be present and filtering is required.

Associated Analytic Story

Windows System Binary Proxy Execution MSIExec

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
An instance of $process_name$ was identified on endpoint $dest$ contacting a remote destination $dest_ip$	35	70	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: 4