Never seen this before?

I was in another forum,and i viewed a topic that another member was claiming that everytime he clicked a specific members name his av would detect a trojan.I did some research and found that you guys are experts in this field,and i wanted to know how this can be possible?I know that in that forum that its been a few days and there hasnt been any awnsers on how this is possible.Im no expert,but i thought this was very rare to view this.

 

Thanks for your reply watermark.Thats interesting info.From what i gather is the guy is even providing pasted info on the detections of the trojan,and his av norton corporate only detects them when he clicks on those specific membername/log/viewtopic/addreply.And he mentioned that his av doesnt detect them anywere else,and they are the same trojan.I have never seen that before myself and i was just amazed to see this.Thanks again.