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.
Rogue.Multiple is the generic detection for Trojan downloaders that install multiple rogue applications like fake antivirus software.
Malwarebytes can remove Rogue.Multiple without further user interaction. The rogue files it may have installed are detected under other names.