Windows Vulnerable 3CX Software

Try in Splunk Security Cloud

Description

The following analytic detects instances of the 3CXDesktopApp.exe with a FileVersion of 18.12.x, leveraging Sysmon logs. This detection focuses on identifying vulnerable versions 18.12.407 and 18.12.416 of the 3CX desktop app. Monitoring this activity is crucial as these specific versions have known vulnerabilities that could be exploited by attackers. If confirmed malicious, exploitation of this vulnerability could lead to unauthorized access, code execution, or further compromise of the affected system, posing significant security risks.

• Type: TTP

• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

• Last Updated: 2024-08-15
• Author: Michael Haag, Splunk
• ID: f2cc1584-46ee-485b-b905-977c067f36de

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1195.002	Compromise Software Supply Chain	Initial Access

Kill Chain Phase

• Delivery

NIST

• DE.CM

CIS20

• CIS 10

CVE

Search

`sysmon` (process_name=3CXDesktopApp.exe OR OriginalFileName=3CXDesktopApp.exe)  FileVersion=18.12.* 
| stats count min(_time) as firstTime max(_time) as lastTime by dest, parent_process_name,process_name, OriginalFileName, CommandLine 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)`
| `windows_vulnerable_3cx_software_filter`

Macros

The SPL above uses the following Macros:

• security_content_ctime
• sysmon

windows_vulnerable_3cx_software_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

• _time
• OriginalFileName
• process_name
• EventID
• CommandLine
• dest
• parent_process_name

How To Implement

To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.

Known False Positives

False positives may be present based on file version, modify the analytic to only look for version between 18.12.407 and 18.12.416 as needed.

Associated Analytic Story

• 3CX Supply Chain Attack

RBA

Risk Score	Impact	Confidence	Message
90.0	100	90	A known vulnerable instance of 3CX Software $process_name$ ran on $dest$, related to a supply chain attack.

The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

• https://www.sentinelone.com/blog/smoothoperator-ongoing-campaign-trojanizes-3cx-software-in-software-supply-chain-attack/
• https://www.cisa.gov/news-events/alerts/2023/03/30/supply-chain-attack-against-3cxdesktopapp
• https://www.reddit.com/r/crowdstrike/comments/125r3uu/20230329_situational_awareness_crowdstrike/
• https://www.3cx.com/community/threads/crowdstrike-endpoint-security-detection-re-3cx-desktop-app.119934/page-2#post-558898
• https://www.3cx.com/community/threads/3cx-desktopapp-security-alert.119951/

Test Dataset

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 | version: 3