Lost 3 Billion VND in Crypto Overnight: A Hard Lesson in Security That 99% of Investors Ignore

Around 2 a.m., I was jolted out of my sleep by a phone call. On the other end was the trembling voice of a long-time crypto trader:

“Hey… my wallet is at zero. Over 3 billion VND… gone in less than 10 minutes.”

At first, I thought his position got liquidated or the project was rug-pulled. But then he said:

“I didn’t confirm anything, didn’t enter a password, there wasn’t even a log of any permission granted… but the money just left on its own.”

—that’s when I knew we weren’t dealing with market risk, but a targeted attack.

He reported it to the police — only to get a heartbreaking response:

“There’s not enough evidence to determine this is a high-tech crime.”

He contacted the wallet’s dev team — the reply was even harsher:

“The transaction is confirmed on-chain, it can’t be reversed. All assets have been dispersed through dozens of anonymous addresses, tracing is nearly impossible.”

That’s the brutal truth of blockchain: lost means lost forever, no one can save you.

So what happened?

When I helped him check all his devices, I almost broke out in a cold sweat.

All the fatal vulnerabilities lay right in his daily habits:

• An old phone used for 4 years, OS not updated since… 2021
• Home WiFi password set as… his child’s birthday
• Installed 2–3 “asset management” apps full of ads, requesting all kinds of access
• And the final blow: seed phrase photographed, saved in the album, synced to the cloud, and even sent via Messenger to transfer devices

To be blunt:

The way he managed his assets was no different than hanging his safe’s key right outside the door.

A hacker doesn’t need to be a genius — just scan your cloud trash, read your clipboard, or exploit OS vulnerabilities to get your seed phrase and drain everything.

In crypto, strong analysis only helps you make money — poor security will make you lose it all.

I’ve witnessed too many tragedies, so I want to say this once, clearly and directly:

If you want to survive — you must have security discipline. No exceptions.

Here are 3 survival principles, worth more than any technical analysis course:

① Completely Separate Sensitive Information — “No Digitizing, No Sharing, No Photos”

Seed phrase, private key, recovery code… → Must be handwritten only, never screenshot, never saved to the cloud, never sent by message.

Ideally:

• Write 2 copies
• Store them in 2 unrelated places (one at home, one at your office or in a safety deposit box)

In the blockchain world: A leak = lost funds. And once lost, it’s irreversible.

② Use a “Dedicated Wallet Device” — A Device Only for Asset Management

Your asset management device must be absolutely clean:

• No random apps installed
• No social media logins
• No browsing strange websites
• Never use public charging cables
• No clipboard syncing

Best practice:

• Use a separate phone
• Factory reset it
• Only install the crypto wallet
• No SIM card
• No Bluetooth
• Only connect to a home network you control

Turn it into a “mini cold wallet.”

③ Network — The Silent Killer: Never Use Your Wallet on Untrusted WiFi

Hackers don’t just attack devices, they attack networks:

• Public WiFi
• Weak WiFi passwords
• Old routers with outdated firmware
• Free VPN apps with ads

→ All can leak your data.

Mandatory habits:

• Change your WiFi password every 3 months
• Turn off WPS on your router
• Never transact over café, airport, or hotel WiFi
• Before opening your wallet, close all background apps

Understand this:

You’re handling assets worth hundreds of millions — don’t operate like you’re just checking Facebook.

Final Lesson: Keeping Your Money Is the Real Skill

Many crypto traders think hackers are a distant threat. But when you put hundreds of millions into a wallet, then use:

• Outdated phones
• Weak WiFi networks
• Ad-filled junk apps
• Automatic cloud backups

… you’re basically inviting thieves right in.

In this world, making money is not hard — keeping it is.

And those who survive the longest aren’t the best traders — they’re the most disciplined about security.