Sounds like spam! Here's some ways to recognise spam: Virus thread: Typical virus spam file sizes - Make a note of them (click on blue link to see)

Tips on how to find music with less spam: How to find music

And, because some spammers might be ultrapeers who you may in fact be connected directly to, we suggest you go to your Connections window, find the ultrapeer you have been connected to for the longest, select it & click the button to remove. Another ultrapeer will connect between a few seconds to a few minutes depending on person & occasion. Wait until your connection settles down. Then search again, see if any improvement. If not, then repeat the process.

For LW 4 to find your Connections window, go to the View menu -> Show/Hide Connections.
For LW 5, go to Tools menu, choose Advanced Tools.