3CX Supply Chain Attack Network Indicators
THIS IS A EXPERIMENTAL DETECTION
This detection has been marked experimental by the Splunk Threat Research team. This means we have not been able to test, simulate, or build datasets for this detection. Use at your own risk. This analytic is NOT supported.
Description
The following analytic identifies DNS queries to domains associated with the 3CX supply chain attack. It leverages the Network_Resolution datamodel to detect these suspicious domain indicators. This activity is significant because it can indicate a potential compromise stemming from the 3CX supply chain attack, which is known for distributing malicious software through trusted updates. If confirmed malicious, this activity could allow attackers to establish a foothold in the network, exfiltrate sensitive data, or further propagate malware, leading to extensive damage and data breaches.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Network_Resolution
- Last Updated: 2024-05-21
- Author: Michael Haag, Splunk
- ID: 791b727c-deec-4fbe-a732-756131b3c5a1
Annotations
Kill Chain Phase
- Delivery
NIST
- DE.CM
CIS20
- CIS 13
CVE
Search
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| tstats `security_content_summariesonly` values(DNS.answer) as IPs min(_time) as firstTime from datamodel=Network_Resolution by DNS.src, DNS.query
| `drop_dm_object_name(DNS)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| lookup 3cx_ioc_domains domain as query OUTPUT Description isIOC
| search isIOC=true
| `3cx_supply_chain_attack_network_indicators_filter`
Macros
The SPL above uses the following Macros:
3cx_supply_chain_attack_network_indicators_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Lookups
The SPL above uses the following Lookups:
- 3cx_ioc_domains with data
Required fields
List of fields required to use this analytic.
- DNS.src
- DNS.query
- _time
How To Implement
To successfully implement this search you need to be ingesting information into the Network Resolution
datamodel in the DNS
node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA''s are installed.
Known False Positives
False positives will be present for accessing the 3cx[.]com website. Remove from the lookup as needed.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
100.0 | 100 | 100 | Indicators related to 3CX supply chain attack have been identified on $src$. |
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: 2