8 million, gone in seconds.

When my friend Xiaoqin called me, she was completely devastated. "Ke'er, it's over... it's all gone..." Her voice was trembling. After a week-long business trip, she came home to find her wallet balance had dropped straight to zero. Report it to the police? The police just said, "If a family member did it, it doesn't count as theft," and that was it.

The whole thing was absurdly simple: her husband helped transfer some funds using their old Android phone at home. The WiFi password hadn’t changed in three years, and the phone’s browser was packed with all sorts of random plugins—one of which was something called "Financial Assistant," installed years ago to grab a promo coupon from some platform.

That lousy plugin had a built-in clipboard monitor. The moment she copied her mnemonic phrase, it was instantly picked up by the hacker's server. 8 million USDT, gone faster than scrolling through TikTok. Not even a transfer record left behind.

**How did your coins disappear?**

This incident actually involved several fatal mistakes.

First mistake: How the mnemonic phrase was transmitted. Many people are used to taking screenshots and sending them via WeChat, or saving them in phone notes or cloud drives. That’s no different from writing your bank card PIN on a sticky note and putting it on the wall. Mnemonic phrase = absolute control. If it leaks, you’re handing over the keys.

Second mistake: Outdated devices. That Android phone hadn’t been updated in years. Security patches? Nonexistent. The "Financial Assistant" browser plugin? Basically just a clipboard hijacker virus—it secretly swaps your wallet address for the hacker’s when you copy it, or uploads your mnemonic phrase the moment you copy it.

Third mistake: Network environment. The home WiFi password hadn’t changed in three years, and the router firmware was ancient. This is even riskier than using public WiFi—once a hacker cracks the WiFi password, they can monitor all device traffic.

What Xiaoqin’s husband did was basically like entering a safe’s combination under a security camera, while reading the password out loud. The technology isn’t complicated, but it’s nearly impossible to guard against.

The crypto world is brutal: there’s no customer service to help retrieve your assets, no bank to freeze a hacker’s account. Lose your private key or leak your mnemonic phrase, and your money is truly gone.

So don’t dismiss basic security measures as a hassle: handwrite your mnemonic phrase on paper and lock it in a safe, never touch any electronic devices with it; update your devices and security patches regularly; install as few browser plugins as possible, and avoid anything from unknown sources; change your WiFi password regularly, and keep your router firmware updated.

Learn from this 8-million-dollar lesson, and I hope you never have to experience it yourself.