I'm a happy Limewire user. The program itself is fine, but as indicated, there is no shortage of dodgy files available for download. Opening the wrong file can wreak havoc on your PC.
When searching for music, always use the "music" rather than "all types" in the search term.
Genuine music files should have an extension like .mp3, a bitrate from about 128 up to about 320, and be around 3-4 MB for a lower bitrate, increasing with higher.
I've never caught malware from the use of it.
But certainly, there are some obvious dodgy files available. Doesn't take long to learn to spot them.