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.
Backdoor.Neutrino is the payload dropped by the Neutrino Exploit Kit. This Backdoor allows the threat actor to download and execute more malware on the infected system.
This backdoor is typically dropped by the Neutrino EK.
Malwarebytes can remove this threat without further user interaction. The Premium version also protects you against exploit kits.