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.
This is the generic detection for a family of obfuscated bundlers.
Malwarebytes can remove Trojan.Crypt.NTH without further interaction. If this Trojan was active on the system, you can expect to find other malware or PUPs as well.