Unfortuately you have a trojan that just started appearing here a few weeks ago.
It's called Flashback. The file you are looking for is Invisible, as noted by the period (.) just preceeding the file name.
Read the link below, OK?
It's serious, and could take your credit/bank information.
Soi get rid of it now.
When you're all clelaned up, Apple has just released a Security Update, that will prevent this from happening again.
Install the most recent java update which advertises itself as being able to remove the trojans.
If you don't want to do these installs then at least go to F_Secure's Flashback Removal Tool web page, download their Flashback trojan detection/removal tool, and follow the instructions you find there.