CoW Swap Pauses Protocol After DNS Hijacking Redirects Frontend to Malicious Site - Unchained

CoW Swap temporarily suspended its protocol on April 14, 2026 after attackers compromised the DNS settings for swap.cow.fi, redirecting visitors to a malicious phishing site. The hijacking began at approximately 14:54 UTC, with on-chain security firm Blockaid issuing the first public warning, flagging cow.fi as malicious and urging users who had connected a wallet to revoke approvals and avoid any interactions with the dApp immediately.

CoW DAO confirmed the attack in a follow-up post at roughly 16:24 UTC, identifying the incident as a DNS hijacking. The team said the underlying CoW Protocol smart contracts were unaffected, but paused the backend and APIs as a precaution while working to resolve the domain. Users who interacted with the frontend after 14:54 UTC were advised to revoke any token approvals using revoke.cash.

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Aave acknowledged the situation and confirmed it had temporarily disabled CoW Swap endpoints for its integrators as a precaution. The incident is part of a broader pattern of frontend and DNS attacks targeting DeFi protocols. In recent months, Blockaid has flagged similar attacks on tokenization platform OpenEden, lending protocol Curvance, and asset manager Maple Finance.

DNS hijacking typically exploits registrar-level weaknesses, such as compromised credentials or social engineering, rather than any flaw in smart contract code. As of publication, CoW DAO had not confirmed full restoration or released a post-mortem. No confirmed user fund losses had been publicly reported.