MetaMask has introduced a new security feature called Added Protection that guarantees an Ethereum or EVM transaction will match the preview a user sees before signing, or the transaction will revert. Announced on September 17, the upgrade makes MetaMask the first self-custody wallet to enforce this match. The wallet provider says the feature closes a long-standing gap that has let malicious contracts slip through transaction previews.
What a Red Pill Attack Is
A red pill attack exploits a blind spot in how most crypto wallets work. Before a user approves a transaction, the wallet simulates it and shows a preview of the expected result. That preview is only a simulation, and nothing previously forced the real transaction to match it. A malicious contract can detect when it is being previewed, show a harmless result such as “You will receive 0.1 ETH,” and then run something entirely different once signed, draining the wallet. Because the preview looks fine, the user has no reason to hesitate before signing.
How Added Protection Works
With the feature active, MetaMask simulates a transaction before signing and locks the expected result into the transaction as a requirement. When the transaction actually executes, the outcome must match what the user was shown. If a red pill contract tries to do anything other than what it promised, the transaction fails automatically and the funds never leave the wallet. The user loses only the network gas fee for the attempt, and MetaMask charges nothing for the feature or the failed transaction. The protection guards against manipulated outcomes rather than ordinary market shifts, and it is especially useful when approving large transactions or interacting with unfamiliar contracts.
Rollout and Industry Context
Added Protection is on by default and can be switched off in the confirmation screen for users who prefer to manage risk themselves. It is now live on MetaMask extension version 13.45 across the 13 EVM networks that support smart accounts through EIP-7702, with mobile support to follow. The launch arrives as MetaMask operates as an independent consumer company after separating from Consensys, and it extends a broader push to harden wallets against on-chain scams, following Blockaid’s recent expansion of onchain monitoring as exploits and infrastructure failures continue to drive crypto losses. The upgrade also matters for anyone funding a crypto casino directly from a MetaMask wallet, since deposit transactions are exactly the kind of unfamiliar-contract interaction Added Protection is built to guard.