Today, I had to deal with a pesky virus for one of my customers. There were over 2,000 instances of it on their web site, so I wrote a little program to check each file and do a repair. I recall doing the same thing 25 years ago for another virus.
I suppose this is just part of the business of using the web.
Do a google search for String.fromCharCode 0242d5 but DON'T click on any of the links. Most of them have the Google malware warning. There's 345,000 pages found. Here is more information about this thing.