A malicious antimeme would be a dark pattern in web design for handling privacy/data/etc. Something designed to satisfy whatever law/regulation requires them to have the option while making the ability to find/remember/interact with it as hard as possible.

Another candidate is the common usage of memory-holing, where important information is removed from public perception maliciously. The Dubai Chocolate thing technically falls into here, as does the whole "war in Iran to distract from the Epstein files" thing. Frankly the whole Epstein stuff is riddled with malicious memes and antimemes to deliberately muddy the waters. Similar to deliberate attempts to inject insane conspiracy beliefs "the moon controls our brains" into conspiracy theories that are too close to something real "mk-ultra".

Consciousness for an antimeme is more of a classification error in my mind, as consciousness as a concept is permanently warped. But you could describe a secret society/dark family secret as a form of living antimeme, hiding some information and preventing it from being shared using a variety of means.