I got the warning. I emailed the Webmaster who responded promptly and graciously to ease my nonexistent fears. Thanks Sheldon, we know you're looking out for these things and I really appreciate it.
If there really were a problem, would it only be dangerous for Windows users?
ETA FF gave me the option of clicking that this isn't an attack site and so I did.
Cheating is an option. . . . Cheaters never win and winners never cheat, but smart knitters who want to retain an iota of sanity do, cheerfully. ~~Kory Stamper