I got hacked at 3:59 AM without clicking anything. My voicemail handed the attacker my Telegram login code.
Here is exactly how it worked, so it doesn't happen to you.
3:54 AM. My phone rings about ten times in a row, No Caller ID. That was not harassment. It was the attack: keep my line busy.
Meanwhile, the attacker asks Telegram to log in with my number and picks "send the code by phone call". My line is busy, so Telegram's robot call lands on my voicemail and reads the code out loud to it.
Carrier voicemail can often be reached remotely, with a default PIN or a spoofed caller ID. He listens to the message. At 3:59 he is in.
Fortunately, the attack was noisy. The calls woke me up. At 4 AM I only wanted to go back to sleep, but I had the presence of mind to check my notifications. Telegram was showing a new login from a device I didn't know. That check is what saved me: I ended his session within minutes. If I had rolled over, the next day would have been a mess.
In those few minutes he had already typed /balance, then /start on every old wallet bot he could find in my chats. He was hunting for funds tied to my Telegram. The bots were long dead and nothing was lost. He still had time to set his own 2FA password on my account.
What would have stopped it:
Telegram two-step verification, with a recovery email. With a password on the account, the code alone is useless.
Your voicemail. Change the PIN, block remote access, or turn it off (##002# cancels call forwarding on most carriers).
Same for WhatsApp and any service that can send a code by voice call.
No seeds, keys or passwords in Saved Messages. Ever.
A burst of masked calls at night is a signal, not a nuisance. Check your notifications and your active sessions.
I have been building in crypto for more than ten years and I had never thought about my voicemail. Check yours today.
