Trojan.Agent refers to a generic Trojan malware detection. It is used for detections that are either associated with no specific malware families or not enough information is available to pinpoint the malware family.
Once executed, it is capable of tracking user online activities, opening affected systems for infiltration to steal personal information and credentials, changing browser and DNS settings.
Backdoor.Tofsee can be distributed via email as attachments. It can also be bundled with other programs.
Malwarebytes can remove Backdoor.Tofsee without further user interaction.
If you find that your system is affected by this, change your passwords immediately.