The Evolution of Web3 Phishing: Drainer as a Service and Malicious Signature Attacks

The most rapidly evolving threat in Web3 security today is the sophisticated phishing campaign targeting user wallets. A major driver of this trend is the proliferation of “Drainer as a Service” (DaaS), a potent toolkit offered by cybercriminal groups.

What is Drainer as a Service (DaaS)?

DaaS is a business model where less technically inclined attackers can rent pre-built, high-quality wallet draining kits. These kits are used to deploy highly convincing fake NFT minting sites, airdrop pages, or counterfeit decentralized applications (Dapps).

The Attack Vector: Malicious Signature Requests

While older scams focused on stealing seed phrases, DaaS-powered attacks focus on tricking users into signing malicious smart contract transactions or messages. High-risk requests frequently employed include:

• setApprovalForAll: This grants the attacker unlimited control over an entire NFT collection.
• Malicious permit functions: The user signs a message allowing token transfer, enabling the attacker to steal assets without needing to pay gas fees themselves.

Once the user signs these requests, the drainer software operating on the backend automatically sweeps all specified assets—ETH, tokens, and NFTs—from the connected wallet. This process is nearly instantaneous, leaving victims with little chance to react.

Mitigation Strategies

Web3 users must meticulously scrutinize every single signature request prompted by their wallet, even if it appears to be a simple “message signing.” If you are prompted for a signature on an unfamiliar site or under pressure, always decline. Furthermore, utilizing hardware wallets for all significant holdings is mandatory to safeguard assets against these sophisticated attacks.