Pop Up Adware in Safari

[RalphTomaccio]

Apparently, I have managed to get a pop up ad virus in Safari. Almost every time I click on a legitimate link in one window or go to a new web site, a new window opens either with some ad, a warning that Flash player is corrupt or needs updating, or "Your system is corrupted with 3 viruses". Very annoying.

I am using a mid-2010 iMac running the latest OS allowed - version 10.13.6. No jokes, please. I'm 73 and my computer needs are minimal. It is serving me just fine for now, except for this issue.

Here's what I've tried so far:
1. Checked Safari Preferences/Security to make sure "block pop up windows" is selected
2. Ran Disk Utility
3. Ran Onyx
4. Reinstalled the OS

My question: Is there any way to get rid of this virus without having to spend money to do so? Any other suggestions?

If not, what is a reasonably priced good piece of software that you recommend?

Your help is most appreciated. TIA

Ralph

 

[Lufbrarunner]

Malwarebytes is good and it's free

 

[RalphTomaccio]

Malwarebytes is good and it's free

I just tried Malwarebytes and, crossing my fingers, it seems to have gotten rid of the problem. Let's hope it remains that way. Thank you, Lufbrarunner!