When connecting to public Wi-Fi (such as at airports, coffee shops, or hotel networks), the network often lacks effective port isolation and encryption. Hackers can eavesdrop on your data, tamper with traffic, and launch phishing attacks within the same local area network. Crypto wallet operations heavily rely on node communication and signature authorization. Once the data link is interfered with, your assets face a risk of theft.
The main risk pathways include the following aspects:
1. Man-in-the-middle (MitM) attacks and transaction data tampering
Hackers use techniques such as ARP spoofing to hijack traffic within the local area network, intercepting the communication between your wallet (or browser extension) and blockchain nodes (RPC Node):
Address substitution: When you initiate a transfer, hackers can silently alter the recipient address while the data is being transmitted, redirecting funds to their own account.
Fake malicious authorization: Hackers modify interaction requests sent from dApps to your wallet, tricking you into signing unlimited token approvals (such as Approve or Permit) and directly draining your assets.
2. Evil Twin Attack
Hackers set up a fake Wi-Fi network with the same name as an official public network (for example, a fake “Airport_Free_WiFi”):
Once your device connects by mistake, all network traffic is routed through the hacker’s device.
Hackers can inject malicious JavaScript into Web3 pages you visit, displaying deceptive pop-ups that ask you to “re-enter your recovery phrase” or “update your wallet.”
3. DNS Hijacking and Domain Phishing
DNS resolution on public Wi-Fi is usually handled by the local network router:
After tampering with DNS records, hackers can redirect the domains of DEXs, decentralized applications, or WalletConnect that you visit to cloned phishing websites.
Phishing pages look identical to official websites, but any attempt to connect, authorize, or enter your private key will expose your keys.
4. Local Network Device Scanning and Trojan Installation
Most public Wi-Fi networks do not enable client isolation:
Attackers on the same network can use scanning tools to probe for open ports and system vulnerabilities on your device.
Attackers can use this opportunity to install clipboard-hijacking malware (which alters copied wallet addresses), keyloggers, or even remotely control devices that haven't received the latest system patches.
Security Recommendations
1. Disconnect from Wi-Fi and switch to mobile data: When transferring crypto assets, signing, or logging in, switch to your phone’s 4G/5G hotspot whenever possible.
2. Use a reliable VPN: If you must use public Wi-Fi, keep an end-to-end encrypted VPN enabled at all times to prevent local network data from being intercepted or tampered with in plain text.
3. Use a hardware wallet (cold wallet): Use a hardware wallet for a second signature confirmation. Even if the network environment has been tampered with, your private key never leaves the device, and you can cross-check the final recipient address on the hardware wallet’s screen.
4. Never enter your recovery phrase: Any pop-up asking you to enter your 12- or 24-word recovery phrase during everyday use, software upgrades, or network reconnections is 100% a phishing attack.$BTC
