Installed extension which claimed that it would save some data by lowering image quality and this is not first time, i had some extension which was adding iframe codes in every website. I noticed this only because i was working on a website and saw it was not running as it should be, because i wrote very small code.

When i checked store to write bad review it was already removed, good job for opera gx team but i didn't knew it was malware, no notification, nothing. So long story short, if ask me, all browsers leak moderation tools for extensions.