
Briefing
The new Eleven Drainer Phishing-as-a-Service (PhaaS) operation has been identified by security researchers, signaling a critical evolution in user-targeted asset theft. This sophisticated criminal enterprise provides end-to-end infrastructure ∞ including cloned websites and malicious smart contract scripts ∞ to rapidly execute large-scale social engineering attacks against individual Web3 wallet holders. The primary consequence is the unauthorized sweeping of tokens, NFTs, and stablecoins by leveraging fraudulent transaction signatures, circumventing traditional smart contract security measures. The professionalized drainer ecosystem was responsible for an estimated $494 million in losses in 2024 , underscoring the massive scale of this ongoing threat class.

Context
The current threat landscape is defined by the proliferation of PhaaS kits, which have lowered the technical barrier for large-scale on-chain fraud. Prior to this group’s emergence, established actors like Angel and Inferno Drainer had already demonstrated the effectiveness of weaponizing token approval mechanisms. This class of attack exploits the human factor and the user’s implicit trust in familiar Web3 interfaces, rather than exploiting a protocol’s core smart contract logic.

Analysis
The Eleven Drainer attack vector begins with a social engineering lure, typically a fake airdrop or project site, directing the user to connect their wallet. The malicious front-end then prompts the user to sign a transaction, often disguised as a simple “connect” or “claim” action. In reality, this signature is a malicious setApprovalForAll or permit call granting the attacker’s contract unlimited spending allowance over the user’s assets.
Once the signature is obtained, the attacker’s back-end script automatically calls the approved function to sweep all available tokens and NFTs from the victim’s wallet in a single, irreversible transaction. This method bypasses the need to compromise a protocol’s smart contract, instead exploiting the trust layer between the user and their wallet interface.

Parameters
- Attack Vector Class ∞ Phishing-as-a-Service (PhaaS). Explanation ∞ Criminal enterprise providing tools for mass-scale social engineering and wallet draining.
- Primary Vulnerability ∞ User Error and Malicious Signature. Explanation ∞ Exploits human inattention to grant unlimited token spending permissions.
- Estimated 2024 Loss ∞ $494 Million. Explanation ∞ Total funds stolen by the broader wallet drainer ecosystem, showing the scale of the threat.
- Victim Target ∞ Individual Web3 Wallet Holders. Explanation ∞ Attack is directed at the user interface and wallet interaction, not a protocol’s core contract.

Outlook
Users must immediately adopt a posture of zero-trust for all transaction signatures and employ real-time transaction simulation tools to verify the true nature of a wallet request before signing. Protocols should integrate client-side security layers that explicitly decode and warn users about unlimited token approvals ( setApprovalForAll ). This incident will likely drive the adoption of EIP-712 structured data signing for clarity and accelerate the development of real-time transaction monitoring and intent-based security solutions to bridge the critical gap in user-side protection.

Verdict
The rise of professionalized wallet drainers shifts the primary security battleground from smart contract code to the user’s execution environment, demanding an immediate overhaul of individual operational security practices.
