When I used to do tech support malvertising was the #1 cause of adware and viruses installed on computers, the usual solution after cleaning the computer was to install uBlock Origin, enable the "malware domains" lists and replace the Internet Explorer shortcut with either Chrome or Firefox (little trick, change the shortcut name to Internet Explorer and change the icon to the blue 'e'). That solution used to keep computers clean for longer periods of time.
Unfortunately the infrastructure I had to work with was a mess made by an incompetent guy, I had to fix things because I was not able to properly prevent them. I could quit that job a few months ago.
The thing about inheriting a mess like that? You will learn more in a very short time than you will in any classroom. At the end of the cleanup there is a very real sense of "I fucking did that!" that cannot be beat. I've cleaned up my share of disasters.
I have definitely learned a lot from that job, it was a horrible and good experience at the same time but I felt like I was not progressing anymore, I was not getting any benefit or experience anymore on that job, for that and other personal reasons I decided to quit.