See
WARNING: Viruses on network you should be aware of! (click on link)
birdy is on the mark: 1. make sure you only get LW from the official site. 2. make sure the anti-spyware/adware programs you use are appropriate & not poorly designed programs as tested & reported on the spyware forum. 3. be careful of what you downld (stay away from files less than 1,000 KB)