help removing installmac malware
I would head straight to sophos where they provide free virus and malware scanning software as well as removal tools.


http://www.sophos.com/en-us/products/free-tools/sophos-antivirus-for-mac-home-edition.aspx


Their product is quite well vetted and used by enterprise and many organizational IT departments. Worst case, you could reboot your Mac into recovery mode and install a fresh OS onto a USB drive and then install the cleaning software there, but from what you've listed a decent tool might clean things up with little muss or fuss.