Weird text on websites

For some weeks now I've seen some weird text on many of the sites I access. What is the world could it be? See attached and thanks for your ideas. ellenc

There is nothing attached.

So sorry. I did upload the jpeg and don't know why it didn't go through. I'll try again. ellen c

Thanks for replying. I use Firefox mostly. As to whether it's random, let me check it out for a couple of days, 'cause I'm not sure. ellenc