Red Screen Virus, Adware or Malware Help

Good evening everyone,

My Safari has recently been hit with some sort of virus that causes it to lock up and show the attached warning boxes. While locked-up it does not allow the windows to be closed, a new address to be input in the URL bar or any of the pull down menus to be accessed. Below are images of the windows while locked up. The first image is a pop-up that requires a clicking of the 'OK' button to get to the following red screen and subsequent pop-up window. I currently have no anti-virus software installed (I know, I know...) and could use some suggestions on which software may be best to help remove whatever virus/adware/malware this may be. Any suggestions on the specific kind of virus this may be would also be appreciated.

I'm obviously not going to call the phone number or click the buttons on the red screen (which don't seem to be actual links).

For reference, my OS is 10.9.5 and my Safari version is 7.1.7. I'm writing this post from Firefox, which seems to work without any issues.

Thanks in advance,

Eric