"After identifying an individual Tor user on the Internet, the NSA uses its network of secret Internet servers to redirect those users to another set of secret Internet servers, with the codename FoxAcid, to infect the user's computer. FoxAcid is an NSA system designed to act as a matchmaker between potential targets and attacks developed by the NSA, giving the agency opportunity to launch prepared attacks against their systems. Once the computer is
successfully attacked, it secretly calls back to a FoxAcid server, which then performs additional attacks on the target computer to ensure that it remains compromised long-term, and continues to provide eavesdropping information"