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Anonymization attacks

Big picture​

Detect and analyze malicious anonymization activity using Tor-VPN feeds.


Tor and VPN infrastructure are used in enabling anonymous communication, where an attacker can leverage anonymity to scan, attack or compromise the target. It’s hard for network security teams to track malicious actors using such anonymization tools. Hence Tor and VPN feeds come into play where the feeds track all the Tor bulk exit nodes as well as most of the anonymizing VPN infrastructure on the internet. The Tor-VPN Dashboard helps network security teams to monitor and respond to any detected activity where they have a clusterwide view and granular control over logs which is critical in stopping the possible attack in early stages.


About Tor and VPN threats​

Tor is a popular anonymization network on the internet. It is also popular among the malicious actors, hacktivist groups, criminal enterprises as the infrastructure hides the real identity of an attacker carrying out malicious activities. To track down such attackers, Tor historically was subject to investigation by various state level intelligence agencies from US and UK for criminal activities such as Silk Road marketplace, Mirai Botnet C&C. Though it’s not possible to completely de-anonymize the attacker. Hence Tor bulk exit feed came into existence to track all the Tor exit IPs over the internet to know attackers using the Tor infrastructure. Over the years, many Tor flaws became public and attackers evolved to leverage Tor network with additional VPN layers. There are many individual VPN providers which have the anonymizing infrastructure. Attackers can use these new breed of VPN providers with existing options like Tor to make sure of anonymity. To help security teams, the X4B vpn feed detects all the major VPN providers on the internet.

Tor-VPN feed types​

Tor Bulk Exit feed The Tor Bulk Exit feed lists available Tor exit nodes on the internet which are used by Tor network. The list is continuously updated and maintained by the Tor project. An attacker using Tor network, is likely to use one of the bulk exit nodes to connect to your infrastructure. The network security teams can detect such activity with Tor bulk exit feed and investigate as required.

X4B VPN feed In recent times it became a trend to use multiple anonymization networks to hide real attacker identity.list of common VPN providers. There are lots of lists of open proxies and tor nodes on the web, but surprisingly few usable ones dedicated to VPN providers and datacenters. This list combines known VPN netblocks and ASNs owned by datacenters and VPN providers. This list doesn't list all VPNs, but should list the vast majority of common ones.

The Calico Cloud Tor-VPN dashboard​

The Tor-VPN dashboard helps network security teams to monitor and respond to any detected activity by Tor and VPN feeds. It provides a cluster context to the detection and shows multiple artifacts e.g. flow logs, filtering controls, a tag cloud and line graph to analyze the activity and respond faster. The Tor-VPN dashboard may be accessed as below:

  • Log in to Calico Cloud Manager, and go to kibana, select dashboard, and select Tor-VPN Dashboard.

Before you begin...​


Privileges to manage GlobalThreatFeed i.e. clusterrole intrusion-detection-controller

We recommend that you turn down the aggregation of flow logs sent to Elasticsearch for configuring threat feeds. If you do not adjust flow logs, Calico Enterprise aggregates over the external IP addresses for allowed traffic, and threat feed searches will not provide useful results (unless the traffic is denied by policy). Go to: FelixConfiguration and set the field, flowLogsFileAggregationKindForAllowed to 1.

How to​

In this section we will look at how to add Tor and VPN feeds to Calico Cloud. Installation process is straightforward as below.

  1. Add threat feed to the cluster. For VPN Feed,
    kubectl apply -f
    For Tor Bulk Exit Feed,
    kubectl apply -f
  2. Now, you can monitor the Dashboard for any malicious activity. The dashboard can be found at Calico Cloud Manager, go to "kibana" and then go to "Dashboard". Select "Tor-VPN Dashboard".
  3. Additionally, feeds can be checked using following command:
    kubectl get globalthreatfeeds

Additional resources​

  • See GlobalThreatFeed resource definition for all configuration options.
  • Check example to Trace and block Suspicious IPs Here