Telegram Scam Targets ERC-2612 Tokens, Drains Crypto Wallets Without Consent

A recent scam on Telegram has been identified, enabling attackers to drain victims' crypto wallets without requiring confirmation for transactions, as reported by users and evidenced by blockchain data.

This scam targets tokens compliant with the ERC-2612 standard, allowing "gas-less" transfers or transfers without Ether (ETH) held in the wallet, ADVN revealed.

Despite not necessitating user approval for transactions, the scam involves tricking users into signing a message, raising concerns as more tokens adopt this standard.

Anonymous User Lost Over $600 Worth of Open Exchange Tokens

According to Cointelegraph, it received reports from a user who allegedly lost more than $600 worth of Open Exchange (OX) tokens after falling victim to a phishing scam on what appeared to be the official Telegram group for the token's developer, OPNX.

Upon joining the group, the user was prompted to connect their wallet to verify their identity, unwittingly providing access to their funds.

"The victim claimed that he never approved a single transaction from the page, yet his funds were stolen anyway," the report added.

In addition, the scam group replicated the Collab.Land Telegram verification system, utilizing a fake version to deceive users into connecting their wallets to malicious sites.

Blockchain data also revealed that the attacker exploited the "transferFrom" function on the OX token contract, an action typically authorized through a separate "approve" transaction by the owner, which was not evident in this case.

Cyberattacker Executed Permit Function on Token Contract

The attacker executed the "Permit" function on the token contract, setting themselves as the spender and the victim's account as the owner, ultimately draining the funds without the traditional approval process.

This exploit highlights a new feature of specific token contracts under the ERC-2612 standard, facilitating transactions without requiring ETH in the wallet.

However, scammers exploit this feature to deceive users into relinquishing their funds by signing messages granting attackers access.

"[It] can be used to change an account's ERC20 allowance (see IERC20.allowance) by presenting a message signed by the account. By not relying on IERC20.approve, the token holder account doesn't need to send a transaction, and thus is not required to hold Ether at all," Web3 developer OpenZeppelin claimed.

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