If you check old headings in this section, you'll find my post with a similar problem,
though not X-rated. (With info from others).
ALL of us, had a problem on our work computers only. And in our case, the problem
was solved by itself. (Hopefully yours will be too).
It may be that our business computers were specifically targeted, and depending on
your IT people, there may not be a lot you can do about on your own.
If the issue doesn't resolve itself soon, since you didn't initiate it, you might make the
problem known to whoever is responsible for your computers at your business.
The one thing you don't want to happen, is a continuing problem with porn on your
work computers. If it's not addressed, and a history of it is discovered by your bosses,
you might be considered a liability to the company.
That's my two cents worth.