Some articles are recommending disabling Java in your browser to stop cyber criminals from attacking your computer and causing the files on your computer to get scrambled until or unless you pay them lots of money. :( See these articles for more information: Danger Danger!
And an article from Homeland Security... http://www.us-cert.gov/cas/techalerts/TA13-010A.html
You can read what I have to say about it here: http://www.trustsecurityconsulting.com/
My take is that upgrading Java to 7.11 with the link in my Trust Security Consulting blog post is probably the best short term solution IF you have Java apps or IF you play Mincraft a lot. If not then I recommend you uninstall it completely and wait for a few months before installing it again.
You will want to be careful about what emails you open and how deep you surf the Internet. Stay on sites that are trusted as much as possible. If your computer is acting strangely then be sure to ask a technical parent or friend for help.