An LLM can do effectively anything that a human can do by typing commands into a shell now.
But yes - this is why banks want to prevent stablecoin issuers from being allowed to grant rewards
(I am not sufficiently expert here to comment on the odds of an outcome like that)
This strikes me as among the biggest macro risks, and (IIRC) is one of the reasons banks are fighting to prohibit stablecoins from granting yield (to keep the banking system working).
A different primitive that is related to stablecoin but not the same thing, popular among banks, is the "deposit token" - basically a stablecoin, but backed by bank deposits rather than 1:1 cash reserve, and operated by banks. eg. JPM's "JPMD": https://www.jpmorgan.com/payments/newsroom/kinexys-usd-digit...
Not sure how popular / active they are yet, but I imagine they will become a bigger deal as stablecoins are further regulated / banks push harder on their own interests.