So you can send a binary SMS to a phone that will pass it to SIM and SIM will interpret it via bytecode, to execute whatever, incl. making the phone to send an outgoing SMS, with requested data, silently, wtf? :D And this is a normal documented thing.
I gather that paranoid people did not exist/have power back then, when this was designed.
Most people outside the field don't know much about all the internals of phones, SIMs, etc., unfortunately...
Reminds me two articles about SIM cards autonomously sending SMS messages (found here on HN long time ago, probably)
https://medium.com/telecom-expert/what-is-at-t-doing-at-1111... https://medium.com/telecom-expert/more-proactive-sims-f8da2e...