I know you say your on a work pc but seems if this was a widespread problem there would be more than you having these. I strongly suggest you really need to run an antivirus sweep on its full settings and I'm 'fairly' confident your pc has something running it shouldn't have running.
Malwarebytes is a very good free second antivirus-malware. If the IT dept. locked down your pc for installing something else, talk to them stating something is going wrong here. On the other hand is it hehe OK for you to be on this site during work?
https://www.malwarebytes.com/mwb-download/
Another one many don't realize, is type the letters MRT in the run command area of the start menu.
This gets run when there is a monthly update is run only on the quick scan setting. For you use the Full scan setting.
And if the IT dept. has locked it down, they tend to hold back security updates till they can make sure it will not cause problems on the work pc's. With holding back updates there are zero day exploits where the scammers will reverse engineer the updates to find what security holes these are plugging up and then exploit them.