How to detect a virus on your computer is easy if you know what symptoms you need to look out for. If two or three of these symptoms happen together, then its very much likely that your system is infected. If the virus is found and the issue not healed by the antivirus tool, you might have to go for manual removal. If you dont have any antivirus software installed, you must immediately reconnect to the internet and download it. If youve scanned the system and got rid of the virus, you would need to recover and reinstall the files or software that were corrupted as a result of the infection.”]
Source: https://hackercombat.com/explaining-how-to-remove-virus-from-system/