Malware (espc firefox hijackers) removeal guide for Mac?

Hi all,

I have a friend with a mac laptop firefox redirect problem. He tried firefox reset and even uninstalling and re-installing and is still have problems with redirects. He doesn't have the problem in chrome. Even odder, apparently he tried upgrading his OS, and STILL has the firefox redirect problem (could malware be hiding in his firefox profile?) So, three questions:

1) Is there a good mac malware removal guide here or somewhere else you folks would recommend?

2) Does Hijackthis work on macs (and/or the other recommended malware programs on the removal guide here)?

3) Is there a majorgeeks mac forum for troubleshooting/malware removal? If not, can you recommend a really good similar site for these sorts of issues on Macs?

Thanks in advance for help with this.