ID | Technique | Tactic |
---|---|---|
T1090 | Proxy | Command And Control |
T1090.003 | Multi-hop Proxy | Command And Control |
Detection: TOR Traffic
Description
The following analytic identifies allowed network traffic to The Onion Router (TOR), an anonymity network often exploited for malicious activities. It leverages data from Next Generation Firewalls, using the Network_Traffic data model to detect traffic where the application is TOR and the action is allowed. This activity is significant as TOR can be used to bypass conventional monitoring, facilitating hacking, data breaches, and illicit content dissemination. If confirmed malicious, this could lead to unauthorized access, data exfiltration, and severe compliance violations, compromising the integrity and security of the network.
Search
1
2| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Network_Traffic where All_Traffic.app=tor AND All_Traffic.action=allowed by All_Traffic.src_ip All_Traffic.dest_ip All_Traffic.dest_port All_Traffic.action
3| `security_content_ctime(firstTime)`
4| `security_content_ctime(lastTime)`
5| `drop_dm_object_name("All_Traffic")`
6| `tor_traffic_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
Palo Alto Network Traffic | Network | 'pan:traffic' |
'screenconnect_palo_traffic' |
N/A |
Macros Used
Name | Value |
---|---|
security_content_ctime | convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$) |
tor_traffic_filter | search * |
tor_traffic_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
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 |
Implementation
In order to properly run this search, Splunk needs to ingest data from Next Generation Firewalls like Palo Alto Networks Firewalls or other network control devices that mediate the traffic allowed into an environment. This is necessary so that the search can identify an 'action' taken on the traffic of interest. The search requires the Network_Traffic data model to be populated.
Known False Positives
None at this time
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
Suspicious network traffic allowed using TOR has been detected from $src_ip$ to $dest_ip$ | 80 | 100 | 80 |
References
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | pan_tor_allowed |
pan:traffic |
Integration | ✅ Passing | Dataset | pan_tor_allowed |
pan:traffic |
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