Thank you.
Sorry for posting in the wrong section. Newbies do that sort of thing.
For closure:
Malwarebytes found nothing. However, a complete removal of Chrome, followed by running CCleaner, followed by a cold boot of the machine before reloading Chrome, provided satisfactory results.
Post Script: The verification images on this site suck little green toads. I have to guess at all of them and it requires multiple attempts before I guess correctly and succeed in posting.