TR/Agent.5663 is classified as a Trojan infection which is good at self-pretending to infected system key files. Once your antivirus detected the attack information of TR/Agent.5663, this attack will immediately spark and act as a rumor spreading in the market like fire. System key files may be infected and lurk inside captaining in the system as system normal files. Under such circumstances, it is hard for antivirus program to have an analysis on the infected files from such countless system legit files.
How to Remove TR/Agent.5663 Completely/ Tips for Trojan Virus Removal