SOMETHING IS HI-JACKING MY YAHOO

My computer is a 2011 I-Mac 27 that runs version 10.12.5 mac0S SIERRA.

I normally have about 10 Tabs open all the time. I get most of my NEWS from the YAHOO site. For several months, I have had a problem with the Yahoo tab. I am cruising along, minding my own business when suddenly the screen goes blank and then up comes a request for me to participate in a survey for Bell Canada.

It does not matter whether I use Safari, Chrome or Firefox. I am not all that experienced with computers so I have no idea how to get rid of this virus. Is there a program out there that will DEFINITELY kill this annoying bug?

Any help will be very much appreciated. If you need more information, kindly ask and I will do my best to provide it quickly.

Thank you in advance,

Tom

Are you running any antivirus or antimalware software on that Mac?

There is a version of Malwarebytes for Mac. I have not tried it, but it my be worth a shot to see if it detects anything.

https://www.malwarebytes.com/mac/

The only piece of software I am running is a product called AVAST and it has not detected the problem. I did try to download Malware Bytes but when Apple updated my Safari the last time, they killed off two of my three blue boxes and one of those was called the Applications Folder. I still have the Downloads Folder and MWB is sitting there as I write to you but it wants me to drag the install box over to the App Folder I no longer have.

The 2nd problem I have is that today is my 73rd birthday and my son just told me he is taking me to a friends cottage in the Kawartha's for the weekend. We are leaving at 11 AM and I have to do a bit of packing. However, I have a dentist appointment on Monday, so I have to be back for that. I have little choice but to put off your help until late Monday. Sorry about that.

Possible help
https://apple.stackexchange.com/ques...folder-to-dock

Enjoy the Birthday!

The antivirus I used to clean up my daughters mac
https://home.sophos.com/mac

To use it Avast will have to be uninstalled first.

Yahoo is notorious for Malware attack Ads ...