Hi ...
Could be the flashback trojan.. if it is, it's not difficult to remove.
Install this update > Java for Mac OS X 10.6 Update 8
That should remove variants of the trojan. Restart your Mac after the update is installed, try Safari.
If it still crashes, run this removal tool > Flashback Removal Tool - F-Secure Weblog : News from the Lab
If that didn't help at all, check out these folders > ~/Library/Internet Plug-Ins and /Library/Internet Plug-Ins.
If you see that plugin, move it to the Trash.
When you post for help, please tell us which Mac OS X you have installed. The more details you provide, the easier to help you 🙂