Hi, Uninstall anything that you put in recently that may have added that See if something is in your install list. Please try anti-malware program : malwarebytes.com/mac and if that fails If need help :

• https://forums.malwarebytes.com/topic/9573-im-infected-what-do-i-do-now/

If want other scanners :

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware

Please let us know if this solved your issue or if need further assistance.

It's important to check your system, but in case Firefox add-ons don't get cleaned in that process, the next step is to check on those:

You can view, disable, and often remove unwanted or unknown extensions on the Add-ons page. Either:

• Command+Shift+a (Windows: Ctrl+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons
• type or paste about:addons in the address bar and press Enter/Return

In the left column of the Add-ons page, click Extensions.

Then cast a critical eye over the list on the right side. Any extensions Firefox installs for built-in features are hidden from this page, so everything listed here is your choice (and your responsibility) to manage. Anything suspicious or that you just do not remember installing or why? If in doubt, disable or remove.

Any improvement?

Then finally, if your home (start) page setting was affected, this article has the steps to change that: How to set the home page.

The solution at first di not seem to work, but finally it did. I t also gave me a way to control things better down the road