At home I use my Linux laptop, and the family uses a Windows PC. Recently I noticed in taskmanager in the Windows PC a process that was connecting to an unknown site with a strange domain name, and I think it is a virus.
I never use the PC to login anywhere, I do everything from the laptop. So am I safe? My home network connection passes through a router, my laptop is connected through wifi, the PC is connected through ethernet cable to the router.
Elaborating on what Psycogeek mentioned above - anything is possible. It would really depend on the virus/malware involved if it is capable of transmitting itself across the network then you are certainly in danger.
Part of the problem you will probably find is your internet connection running slow as more than likely your infected PC is being used as a zombie/spambot/spam mail relay. Couple that with your IP getting blacklisted aswell as the virus possibly taking advantage of other things it might be programmed to find eg mail accounts, address books, spreading documents.
Obviously the 'quick' solution would be to unplug the infected PC from your network, the more perminent solution - clear it! Malware Scanners are free and there are Free Anti-Virus Solutions.
Never say never in computer security :o)
I'd say your laptop is relatively safe, because most Windows viruses won't be looking for Linux machines to infect. However, it's certainly possible for a virus to contain a payload that will infect Windows machines one way, and try to exploit Linux machines another. Make sure you have a firewall in place on the laptop, and take care of any other basic security practices (the Linux security how-to is one guide).
The answer, though, is really to fix the problem. There's free software available from Microsoft (Security Essentials and Malicious Software Removal Tool; see the Microsoft security site to download) that will help fix a virus or spyware infection; other tools are available as well. If you don't have admin on the PC, perhaps point out the damage that a virus could do to files, and the Internet details that could be compromised (like bank details, etc.) to those that have.
