There are reports today of a new social engineering attempt to install an infection onto your PC. This is tied FireFox and Windows, so if you are not using both of those, you have nothing to worry about. If this applies to you, then there are several things to be aware of.
One is something that I cam across this morning, when browsing a web site using FireFox to what I believed was a valid web site, but potentially could have been hacked. What appeared to pop up was a small window running a Microsoft Security tool. Since I knew that this was a desktop application and not a browser app, I tried to drag it outside of the browser window and could not. At that point, I knew that it was not legitimate. Had I have agreed to install something, I would have been infected and chose to kill the browser window.
The other still involves FireFox and Windows, is another situation where you go to an infected web site and they redirect you to what looks to be a very realistic Windows Update screen. It is not a valid Windows Update page and clicking on the update will infect your PC.
Anytime that something does not look right, you should take the time to take a second look before agreeing to install something.