The hot wallet, however, remains constantly connected to the internet. This opens the door to several possible attacks.

Why a cold wallet is more protective

A hot wallet (Metamask, Exodus, Trust Wallet , etc.) stores the private key on a connected device. A vulnerability in the browser or a malicious extension could allow a hacker to intercept the key or initiate a fraudulent transaction. A cold wallet never allows the key to leave the device, even if the computer is compromised.

Common risks for a hot wallet

• Code injection into the browser via a fraudulent extension
• Session theft or seed recovery
• Cloning a dApp that pushes the user to approve unlimited permissions

With a cold wallet , an attack cannot remotely drain funds. The hacker must physically possess the key and validate the signature on it, making the operation impractical.

Use a VPN on public connections

Wallet hacks often succeed when the victim connects unprotected to a public network. A hotel hotspot, a café, or an airport allows an attacker to position themselves between the user and the website they are visiting. When a request is transmitted unencrypted, the attacker can retrieve information, redirect the connection to a fake website, or steal a session.

A VPN (NordVPN, VeePN , ProtonVPN, or others) encrypts your traffic. Even if someone intercepts the data, they can't read anything. Some DeFi use them, especially when they need to connect to a wallet while on the go.

Concrete examples of attacks on a public network

• Redirection to a fake exchange website with an almost identical URL
• Retrieving a session cookie to open an account without a password
• IP address tracking followed by targeting with a personalized phishing attack

A VPN doesn't prevent a bad investment , but it does prevent a hacker from monitoring or hijacking the connection. When access to the wallet is through a browser connected to an open Wi-Fi network, the encryption layer limits the attack surface.

Verify all transactions before signing

Most crypto hacks don't involve stealing the private key. The trap lies in tricking the victim into signing a contract they don't understand. When a wallet connects to a dApp , the dApp can request access to the wallet's tokens. A contract might then contain a function that allows funds to be transferred to an address controlled by the attacker.

How a fake dApp empties a wallet

• The user clicks on a link received by message or on a group
• The page looks like a well-known platform: airdrop , DeFi, staking
• The wallet displays a request for approval.
• The transaction allows a contract to spend all the tokens indefinitely.
• The victim thinks they are claiming a reward, but in reality they are transferring access

Fake interfaces are common. They are often copied from recognized protocols, with a similar name. To avoid signing a malicious contract, you must examine the website address, verify that the platform is legitimate, and read what the wallet displays. On Metamask, permissions are visible in the signing window. If the transaction authorizes a contract to spend an entire token when you haven't clicked on anything suggesting a transaction, this is a major risk.

What to check before validating a contract

• Full website address, not just the logo
• Name of the contract requesting authorization
• Amount the contract is intended to manage: limited or unlimited
• Presence of the protocol in a public database or on an aggregator

Store the recovery phrase offline

The seed phrase is the wallet's true ownership. Whoever possesses it can restore the wallet on any device, leaving no trace. A digital copy of this phrase transforms a hack into instant theft. A file on a computer, a note in the cloud, a screenshot, or an email are all easy targets.

Seed theft methods

• Malware that scans the computer looking for terms such as “seed”, “mnemonic”, and “private key”
• Phishing via fake recovery forms
• Modified browser extensions

Keeping the phrase offline prevents remote theft. Some use paper, others a fireproof metal plate. The important thing is to prevent a copy from being retrieved by software or an attacker.

Revoke permissions granted to contracts

Each signed agreement remains active until revoked. A contract authorized in 2023 could be exploited in 2025 if its developer disappears or their address is compromised. Some tools allow you to view and remove these authorizations. This regular verification prevents an old or abandoned contract from being used as an entry point.

Recognizing the signs of a scam

crypto hacks exploit psychology. The most lucrative scams promise airdrops, cloud mining, reverse yields, or instant rewards. A first transfer unlocks a second, then a third. At each stage, the protocol requests additional permissions until the wallet is emptied.

Common warning signs

• Aggressive promotion in a Telegram or Discord group
• Modified URLs with a missing letter or a strange subdomain
• Request for seed or private key
• Rewards that are too quick or too high

A legitimate protocol never requires the seed phrase. The only legitimate procedure is to sign from your wallet, without revealing access.

Compare the dAppbefore use

A well-known dApp leaves verifiable traces: official addresses, public documentation, audits, communities, integrations. An anonymous project, created two weeks ago, without audits or transparent announcements, presents a disproportionate risk. Prudence dictates checking the contract in a web browser and comparing it with the official address published by the project.

Conclusion

Web3 security relies on simple reflexes: only sign what you understand, keep your wallets separate, keep your seed money offline, use a VPN when traveling, and prefer a cold wallet for large amounts. Crypto hacks target distracted users, not the blockchain. The more verified transactions are, the less a hacker can manipulate a contract or hijack a connection. The best protection remains mastering the actions and understanding what happens during a signature.