How to get rid of a virus on my computer.

Your Mac does not have a virus.

If you force quit Safari and the restart it with the Shift key depressed that should stop the Javascript.

There are no viruses that can attack your Mac. AV software developers are selling a cure for a disease that doesn't exist. And they are renowned for borking Mac systems.

A Mac can pick up browser pop-ups and the like, but not if you just use common sense. You really have to actively invite some malware in for it to happen. That means downloading and knowingly giving your password for it to download. Mac provides all the protection you need with SIP (System Integrity Protection). If you do happen to download adware use MalwareBytes.to get rid of it.

About System Integrity Protection on your Mac - Apple Support

Also, stay away from programs that purport to "clean your Mac". Your Mac needs no cleaning, all that is taken care of quite well by the system

Effective defenses against malware and other threats

conniefromkenwood wrote:

I have a virus on my computer. whenever I go to a site like Kiva or ebay (sites that are selling something) I get a pop up and can't procede. How do I get rid of this?

As Allan pointed out, you don't have a virus, as there are no viruses for OS X currently floating around. You either have adware installed on your computer, which will cause the pop-ups, or you're encountering a browser hijacker. To get rid of the browser hijacker, quit Safari, then start it in Safe Mode by holding down the Shift key as you click on the icon in your Dock. This prevents previously opened tabs/windows from reopening.

To get rid of the adware, you have two options:

• Download Malwarebytes' Anti-Malware for Mac. It was developed by a trusted and respected contributor here. It's a simple, non-intrusive program that deletes known malware/adware from your hard drive. That's all it does. It doesn't add anything and it doesn't take away anything else. Unlike anti-virus programs, it doesn't run in the background of your computer, using up resources, and also unlike anti-virus programs (which are unnecessary on Macs), it doesn't actively prevent malware or adware infections. Its sole purpose is removing them.
• Restart your computer. According to a change made on April 26, 2016 to the following support article, El Capitan removes adware, but only at login. Stop pop-up ads in Safari - Apple Support

There is no virus, and you should never use any kind of "anti-virus" or "anti-malware" software on a Mac for any reason. That's how you cause problems, not how you solve them.

Linc Davis wrote:

There is no virus, and you should never use any kind of "anti-virus" or "anti-malware" software on a Mac for any reason. That's how you cause problems, not how you solve them.

This is incorrect. Anti-virus programs and Malwarebytes are not the same kind of entity and they should not be treated the same, as they perform two wildly different functions and operate in two wildly different ways. This is like comparing a Rolls Royce to a shoe.