Not malicious per se, GMT.exe is undesirable software and adware as such.
Read here:
https://www.bleepingcomputer.com/startups/GMT.exe-1883.htmlWait for a final verdict by avast team, as it comes with their definitions. 'IDP generic' means that the detection was performed by an Identity Protection detection component of your antivirus and it is a generalized file that got detected. It is an identification used by av-vendors to denote a identity theft program (executable), as IDP stands for Identity Detection Protection. But as said also by Pondus, you should wait for a final answer from the horse's mouth, that is an avast team member.
polonus