At one time, if you are Mozilla Firefox users and once you've found looks like the following.
Then, press "Alt + F4" immediately, to close the Firefox Browser (or it could be by using Task Manager / Alt + CTRL + Del). Why is that? Because that's a fake update, not firefox update, and if you follow the instructions indicated, then you will install the malware, which was identified by "Rogueware". and not updated your Firefox as expected. After closing the browser, you should immediately run your antivirus program and do scanning to your PC. to ensure that Rougeware viruses didn't infect your PC .
According to one of antivirus software company F-Secure, that's a trick used by cyber criminals to fool users into downloading the malware .