I'm not sure. There are what is known as seedboxes, which is where multiple users are joined together. Some information here Seedbox - Wikipedia, the free encyclopedia. That might explain the multiple vendors issue. Though I have never seen that before. Seedboxes I've come across before were usually named with linux in it somewhere.

By the looks though, and I might be wrong, the file is one of those free-to-distribute, non-copyright files made available to the public from time to time to help advertise a particular music or video or literary artist. From memory FrostClick is involved in this kind of media distribution. Vuse/Azureus does something similar or with samples of larger work. I am not sure how FrostClick works but the FW site might even help kick-start some such torrents.

Should you remove it? If your ratio on it is good and you feel uncomfortable about it then perhaps yes. Via Vuse I've had some super good ratios on such files but they eventually lose popularity because of not being a recent release and the publicity surrounding it getting hidden by time.