When I open any site, I sometimes see unknown images replacing the original images on the website. They are not ads and can't be clicked. Just random images of people, cartoons etc.
When I refresh the page, the fake images are gone.
It actually started when I was using Windows 7 - Firefox browser & I installed some plugin I don't remember.
This problem was temporarily resolved when I installed Windows 10 (with format C:) and I installed Malwarebytes and Bitdefender. However, when I removed Malwarebytes temporarily due to an error, fake images started appearing again on the websites.
It happens when I open any site containing images, like free sites on weebly.com.
It happens on my computer and my Android phone. I didn't see it in other PCs in the same network. I have tried two different internet connection networks on my PC, the problem is same.
I am using Opera Browser with no add-ons, extensions etc. and I regularly clean the temporary files using CCleaner utility.
I checked the startup and didn't find anything suspicious. I have very few apps enabled on startup. Plus I also checked Control panel for installed programs I don't recognize. I have a free version of Win 10.
I opened the image link in a new tab, & it was fine (original image- not the fake one replacing it)
The last thing I did was installing software (Autodesk Maya or Unity 3d I think)
Where is the problem? I've been trying to solve this for the last 3 months.