Cobalt Strike’s Covert VPN feature now supports ICMP as one of its channels. Covert VPN is Cobalt Strike’s layer-2 pivoting capability. If you’re curious about how this technology works, I released some source code a few weeks ago.
The ICMP data channel is a turn-key way to demonstrate ICMP as an exfiltration channel if you need to prove a point. Here’s a video demonstrating Covert VPN’s ICMP channel with a server in Amazon’s EC2:
I don’t expect you to VPN all the things, but I’m excited. This feature is a step towards other work with ICMP in the future.
The ICMP VPN channel is available in today’s 2.2 release of Cobalt Strike. This release also touches and improves many of Cobalt Strike’s other features. The VNC server injection process was rewritten to better evade host-based firewalls. The spear phishing tool now handles message templates with embedded image attachments. You also get several bug fixes too. I recommend that you read the release notes for the full list of changes.