Mere moments after releasing 3.6.2, Mozilla has pushed out 3.6.3 to fix a critical security flaw. Here's their explanation: http://www.mozilla.com/en-US/firefox/3.6.3/releasenotes/ I detest updating Firefox. But it's necessary and needs to be done now. Update from within. Ask if you don't know how.
Foxit Reader has also updated; do this from within the program, or download here if not already installed: http://www.filehippo.com/download_foxit/
While you're at it, you may be interested in some of the tools found in Process Explorer. It will provide a ton of information about what's running on your computer - now it would great if somebody added on a simple translation of what it all means and what to do with all that information. Get it here: http://www.filehippo.com/download_process_explorer/