This appears to be illegitimate Opera. I do not have any "Opera Stable" on my end. Which means it could be a fake browser, browser hijacker or some form of anti-malware. I would recommend doing a thorough clear of your system and see if that solves the issues. Steps below:

Restart your PC in “Safe mode with networking.” Install and run RKill to kill malicious processes and services (Might have issues with Windows 10, feel free to skip this if it does) Check your Programs and features and see if there are any new recently installed programs that you don’t recognize. If there are, remove them. Do a full scan with anti-virus software of your choice or use Windows Defender (offline) to clean up initial infections. Scan your PC with Hitman Pro, Malwarebytes, and AdwCleaner. Multiple anti-malware solutions will confirm that the threat was removed. Clean up your Registry and Cached files with CCleaner Restart your PC in normal mode and do an additional scan to confirm that the malware is gone.

These steps should clean up any malicious files from your PC. Additionally, I recommend installing some form of Adblock on your PC just to get rid of ad-spread malware. Good luck!