The trader lost 0.85 BTC due to an address substitution attack in Electrum—by accidentally bumping the fee himself. According to the trader’s account, 0.85 BTC—about 90% of his savings—was sent somewhere other than intended. It all began with a move to a cold wallet using Tails and Electrum, which he had previously tested with smaller amounts. The transaction got stuck as “local,” and Electrum flagged the fee as too low. When attempting to bump the fee via RBF, the recipient address was supposed to change automatically—to one ending identically to the real address. The trader had verified this address multiple times before. This is classic address substitution attack behavior: attackers rely on users overlooking the ending characters, which the eye tends to skip. Reports suggest the loss resulted from a vulnerability in Electrum’s RBF implementation, not from lost keys. It hurts twice as much because it was his first day of vacation, and he had planned for a calm, relaxed hold. Instead of securing his cold wallet, he got a lesson: even 10 years of experience won’t protect you from one wrong click. XD Source: https://t.co/4QHHi4qoHZ