The following analytic looks for allowed network traffic to The Onion Router(TOR), a benign anonymity network which can be abused for a variety of nefarious purposes. Detecting Tor traffic is paramount for upholding network security and mitigating potential threats. Tor's capacity to provide users with anonymity has been exploited by cybercriminals for activities like hacking, data breaches, and illicit content dissemination. Additionally, organizations must monitor Tor usage within their networks to ensure compliance with policies and regulations, as it can bypass conventional monitoring and filtering measures. Lastly, the ability to identify Tor traffic empowers security teams to promptly investigate and address potential security incidents, fortifying the protection of sensitive data and preserving the integrity of the network environment.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Network_Traffic
- Last Updated: 2023-09-20
- Author: David Dorsey, Bhavin Patel, Splunk
- ID: ea688274-9c06-4473-b951-e4cb7a5d7a45
Kill Chain Phase
- Command and Control
- CIS 13
1 2 3 4 5 6 | 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 | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `drop_dm_object_name("All_Traffic")` | `tor_traffic_filter`
The SPL above uses the following Macros:
tor_traffic_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
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
|80.0||100||80||Suspicious network traffic allowed using TOR has been detected from $src_ip$ to $dest_ip$|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
source | version: 3