Ask HN: I experienced an Attack on Telegram and simcards gone!!!

Hello Today, I got a suspicious message from a stranger Telegram user. After some minutes, I opened the notification and only read the message without opening any link. Then immediately, I got an error about no service availability for my simcards. I do not remember the exact error message but it was something like that. I restarted my phone immediately and re-insert the simcards (from different operators in different countries). But, none of them connects to network anymore.

My Telegram account is still accessible and I checked no other sessions are alive on unknown devices.

I turned off my phone which is Android (Samsung). I also blocked my phone number for now.

I am "sure" it was not a furtuitous and bad chance. Everything happened in 1 second. The message was saying "I am looking for my father in Germany..." and the user name had strange characters. I can also share the user name in comments but I feel that it might put the others in risk as well.

AI says : Some bots are front‑ends for leaked operator or government databases (e.g., bots that look up names, addresses, or vehicle data by phone number). Malicious apps or malware on your phone can steal SIM‑related data (or your phone number) and then exfiltrate it to a Telegram bot as a command‑and‑control channel.

Does anyone know what happened ? What actions shall I take besides changing passwords and enabling 2FA for email, messengers, ... accounts?