Trojan.brisv.a HELP!!

My Norton Antivirus just detected this virus on my hard drive. I tried repairing it but Norton can only quarantine it. There is a removal tool available on Norton's website but it's only for PC's. I would simply do a complete system restore but it won't let me back up my files (every time I try and copy them to an external HD it will copy a bunch and then say that a file cannot be read.

 

Any suggestions??