Astff.com alerts in your browser are the evidence of a horrible adware to be currently installed and running in your system. It is quite likely that this particular adware got installed into your PC as a result of you downloading and installing some cost-free software.
Jvrye.com is a scary pop-up warning which may display the load of intrusive alerts saying that your computer is infected with a horrible malware. Then these pop-ups will additionally suggest you to call certain toll-free helpline in order to supposedly speak with Microsoft Customer Support representatives. However, these people who stand behind such pop-ups are simply the bunch of cyber frauds who simply hunt for your money. They do not care at all about helping your PC to become free of malware.