Briefing
A new and highly active Phishing-as-a-Service (PhaaS) operation, dubbed “Eleven Drainer,” has emerged, professionalizing the deployment of sophisticated wallet-draining malware against individual digital asset holders. This syndicate provides a complete, updated malicious toolkit → including cloned websites and smart contract scripts → to affiliate scammers, significantly lowering the technical barrier for mass theft. The primary consequence is a spike in user-side asset compromise, as this model bypasses traditional protocol audits by exploiting the human element and token approval logic. The total losses attributed to the drainer-as-a-service ecosystem exceeded $494 million in the previous year, a threat vector that Eleven Drainer is now rapidly expanding.
Context
The threat landscape was already defined by professionalized PhaaS operations, such as the now-prominent Angel Drainer and its predecessors, which established the blueprint for high-volume, low-effort crypto theft. This prevailing risk is rooted in the architecture of token standards, where user-granted approve and permit functions create a standing attack surface that is often overlooked in favor of core protocol contract security. The systemic vulnerability is less about a single line of protocol code and more about the user’s operational security posture and the necessity of signing external transaction requests.
Analysis
The Eleven Drainer attack vector is a social engineering-driven phishing campaign that culminates in a malicious smart contract transaction. The attacker first lures a victim via deceptive promises (e.g. airdrops, exclusive mints) to a cloned website that mimics a legitimate dApp. Once the victim connects their wallet, the site prompts a signature request that appears benign but is, in fact, a pre-signed transaction using the permit or approve function. By signing this, the user grants the attacker’s contract unlimited or high-value spending permission over their assets, allowing the drainer script to immediately and autonomously sweep all approved tokens from the wallet in a single, irreversible transaction.
Parameters
- Threat Actor Model → Phishing-as-a-Service (PhaaS) – A subscription-based model providing malicious infrastructure to affiliate scammers.
- Primary Exploit Function → Token Approval/Permit Signature – The core vulnerability is tricking users into signing a transaction that grants the attacker’s address spending rights over their tokens.
- Annualized Loss Metric → $494 Million – The estimated total loss attributed to the broader drainer ecosystem in the previous year, which this new group now compounds.
- Targeted Asset Type → Hot Wallet Assets – Funds held in software wallets connected to the malicious dApp interface.
Outlook
The immediate mitigation for all users is to treat all unsolicited digital asset communications as hostile and to maintain a rigorous regimen of token approval revocation using on-chain tools. This incident will accelerate the industry’s shift toward hardware-enforced transaction signing and the adoption of “session key” standards that limit approval scope to single, time-bound transactions. Protocols must prioritize user education on the risks of permit signatures and implement real-time transaction simulation tools that clearly translate the cryptic hex data into a human-readable warning before a signature is executed.
