Working in Mandrake 10.0 on a single non-networked computer, and I think I have a security issue. My system monitor shows network activity as high as 75% when I am not using any network related stuff (browser, streaming media, GAIM, ect). Any suggestions?
Also, could security issues with Internet Explorer effect Linux when I am using IE through Crossover?
Thanks much.
Penguins rule.

Take a look at the output of netstat -pantu for any connections or daemons that seem abnormal. Also take a look at ps aux and top for abnormal processes. It's also a good idea to run a scan with chkrootkit and/or rootkit hunter.

With regards to IE via crossover, I really don't know. I'd resort to wget before putting IE on a Linux system (personally I think Mozilla/Firefox are much better browsers), but that's just my opinion.

I have no personal experience in running IE with Wine/XOver, but my guess is that the only security risk you run is if/when you connect to a network of some sort. Any exploit for IE that would take effect would have no effect on system files since it won't be able to write to them, but if you are determined to use IE on Linux, I would make sure you have your important documents and files backed up somewhere safe... who knows what will happen with IE on the rampage through your /home?

As for your 75% network traffic, have you (somehow) got a DHCP client running in the background looking for a server? You may also find some traffic on your loopback address (127.0.0.1) as some thing simply won't work without any network, so they use the loopback.