"I use Linux were nothing but a firewall is required."
I really wish you wouldn't perpetuate that myth..
According to CERT (US computer emergency readiness team) -
"Phalanx, which dates back to 2005, is a self-injecting kernel rootkit designed for the Linux 2.6 branch. It allows an attacker to hide files, processes and sockets and includes a tty sniffer, a tty connectback-backdoor, and auto injection on boot.
Details on the attacks — and targets — remain scarce but it’s a safe bet this is linked to the Debian random number generator flaw that surfaced earlier this year. A working exploit for that vulnerability is publicly available."Just one of many ..Phalanx2 is out now, even the repositories have been hacked. Fedora had to do a complete rebuild for Red Hat repository a couple years ago. If you trust the Linux community (hundreds of thousands of users) you'll be fine

, except for passing along windows virii inadvertantly.
Until you get targeted. If someone wants in bad enough they will get in, and your browser will read a redirect just as fast as any other if it is hidden correctly.
I would give more examples, but they would be techy and include the known exploits which are best not publicly discussed. A little research at the CERT site will reveal recent exploits.
..the more ya know ..