[XTunnel](https://attack.mitre.org/software/S0117) a VPN-like network proxy tool that can relay traffic between a C2 server and a victim. It was first seen in May 2013 and reportedly used by [APT28](https://attack.mitre.org/groups/G0007) during the compromise of the Democratic National Committee. (Citation: Crowdstrike DNC June 2016) (Citation: Invincea XTunnel) (Citation: ESET Sednit Part 2)