First, let me make it clear that I'm not saying that you have been infected by this Blackhole Exploit Kit. I cannot really make that call via forum posts. The fact that antivirus tools are not finding anything wrong and yet your computer is acting just like it would for this particular infection - might mean that you have been blessed with a version that the AV companies have not detected yet.
I'm not an expert on this infection (or any other infections) but I am a student of this one. If you understood a bit about how it works, you would understand why antivirus tools may fail to detect it. Here is a
nice article about it. At least read the section named "
What are BEPs?" and the first part of the section named "
The Infection Process". If you want a feel for what each of the 16
known versions of this exploit does - glance at
this blog.
If the e-mail that sent you a PDF is from a reputable source, then you are probably okay. Hopefully your PDF reader is up to date.
You probably only use Java inside of a web browser and some game websites require it.
e.g.
Bookworm on Yahoo! Games
You might also use java if you change certain things on Android based smartphones... and/or to develop/debug smartphone apps.
If you uninstall java and you visit a website that requires it - the website will tell you that you need it. You can then decide if it is really worth it to re-install java just to see that part of that website or play that game. You might never miss java. You might never visit a website that uses it - at least that you noticed using it. That is how some versions of the Blackhole Exploit Kit gets you. You can visit an infected website and the exploit starts java inside your browser & does its bad things.
The reason why I say to uninstall every copy of java is - I have cleaned up older computers that have had as many as a dozen different versions installed (taking up more than a gig of space). For a long time, updating java would not uninstall the old version, it just installs a whole new copy of java - so things got messy real fast. Your system might be new enough to not have too many versions installed - or you might not have updated java, so there might only be one version on the computer.
If you Google...
"uninstall java" security
...you will find lot of articles where people suggest living without java. Like I said, it just depends on if you need it and the best way to find out if you need it is to uninstall it and just see if you miss it.
If you decide that you want to put it back - I suggest that you get it from
filehippo instead of from the
Oracle's website. The reason being: Oracle's website is suggesting "version 6 update 31" [which means that there has been 31 updates to version 6]. Version 7 has been out for a while now and has had 3 updates. You will probably never notice the difference if you install version 7 now (and keep it updated).
You have a 64 bit operating system - but you are probably using a 32 bit version of Internet Explorer of Firefox...... that is why I linked you to the 32 bit version of java - should you want to re-install it.
