Ok, here's the thing. A "silent killer" isn't a virus and adware is also no virus. Limewire has never come with a virus, but... It used to come with loads of spyware/adware. My brother downloaded it recently and said it was because it no longer comes with spyware. He said he did a scan with Spybot S&D and didn't find anything out of the ordinary, but I'm not sure.
Also, be awefully careful about what you download with Limewire. It has more security flaws with some options. Most files that look like legit downloads may actually be repackaged executables or just plain viruses.
I completely recommend using Shareaza instead, as it has a great support for security: http://www.shareaza-security.com/
Be sure to get Shareaza 2.2.1 first (clicky)!