Hollow Knight Silksong has attracted a lot of attention. However, some have only "heard" about the game and are not particularly involved in the industry, so they don't know that there is no mobile version.
Hackers and scammers have targeted such people. An advertisement for a "mobile version" of Silksong has begun to appear online, designed as official promotional materials from Team Cherry.
Attentive users told the developers about this — Matthew Griffin replied: "The best thing you can do is file a complaint on YouTube if you see something like this."