Name: U321 Backdoor Category: RAT Alias: Backdoor.Froobot.12 Advice: Remove Risk: Elevated Risk Elevated threats are usually threats that fall into the range of adware in which data about a user's habits are tracked and sent back to a server for analysis without your consent or knowledge. Description: Signatures: process: systray.exe: MD5 Hash: 4a9409ac0f9dc919834... process: u321 client.exe: MD5 Hash: 70b7c5f82f8056784e9.. Type: RAT - A Remote Administration Tool (RAT) is a Trojan type of software that when run, provides an attacker with the capability of remotely controlling a user's computer (victim) over the Internet. The attacker usually has full access to functions on the victim's computer. The victim's computer usually listens on the Internet for the attacker's commands.