In recent years, with the rapid development of DeFi (Decentralized Finance), phishing attack methods targeting smart contracts have continuously evolved, with malicious approval becoming one of the most commonly used attack methods by hackers. Unlike traditional phishing, this attack technique is more covert, and users often have their assets stolen due to erroneous authorization actions without being aware.
Attack principles
The core of malicious authorization attacks lies in inducing users to grant token operation permissions to malicious contracts or phishing DApps (decentralized applications). Attackers usually will:
Faking well-known DApp interfaces: Impersonating platforms like Uniswap and OpenSea to deceive users into connecting their wallets and signing authorization transactions.
Implanting malicious contracts: Hiding high-privilege approve or increaseAllowance functions within seemingly normal transactions to gain unlimited transfer rights to user tokens.
Utilizing social engineering: Inducing users to interact with malicious contracts through airdrops, fake promotions, and other methods.
Preventive measures
Check authorization records: Regularly use tools like Revoke.cash to clean up unnecessary authorizations.
Be cautious of unfamiliar DApps: Avoid clicking on unknown links and prioritize accessing DeFi platforms through official channels.
Review transaction details: Carefully verify the contract address and authorization limits before signing in the wallet to avoid signing suspicious approve requests.
Malicious authorization attacks have become a significant threat in the DeFi ecosystem. Users need to enhance their security awareness to avoid asset losses due to momentary negligence.
