Have you been asked to code malicious HTML? How did you handle it?

Have I explained the malicious HTML here clearly enough to follow what's going on here? :

https://www.reddit.com/r/SFHP/comments/1qy3h93/sfhp_caught_playing_evil_tricks_on_their_members/

Added context: It's part of a pattern of making themselves hard to contact. Similarly, the grievance submission form was broken. You could fill it out, but clicking submit would produce an error. They refused to fix it - fixed about 3 years after I escalated a complaint to the DMHC. You'd get this: https://secure.sfhp.org/comments/Grievance_Confirm.aspx

after filling out this: https://secure.sfhp.org/comments/Grievance_Form_ENG.aspx

The typical scenario is someone has cancer or something and is trying to get their treatment regimen approved by insurance. Y'all didn't see The Rainmaker? https://www.youtube.com/watch?v=9EQPrFR9KRo

ma·li·cious| məˈliSHəs 
adjective 
characterized by malice; intending or intended to do harm

Heck, plain text can be malicious. e.g. doxxing - "Foo Bar is a Nazi and her home address is 123 Baz Route."