It is possible it has been infected.
Run a reputable product such as MalwareBytes to see if there's anything. To be 100% sure a clean install of your O/S would be in order.
Also, be aware they may have gotten access to any account information that was on your machine. That could include bank, e-mail, social media, etc. websites and those could be compromised. Changing passwords might be advisable. Make the changes from a machine that you know is clean.