This column contains the steps I take when I try to verify my own computers (or those of my friends or neighbors) aren’t infected. The first thing I do is to look for suspicious autostarting programs. From there, I close all software that might possibly connect to the Internet, starting with the browser, social network tools, or other memory resident tools. The author also looks for unneeded browser add-ons and removes any I don’t recognize or don’t need. If you want that, format your hard drive and reinstall everything from vendor-distributed media and content.”]
Source: https://www.csoonline.com/article/2616368/how-the-pros-sniff-out-a-malware-infection.html