Dragonfly Managing Partner: Arbitrum Security Council used emergency powers to inject ArbitrumUnsignedTxType and transfer attackers' funds

Foresight News reports that Dragonfly Managing Partner Haseeb Qureshi released an analysis regarding the “Arbitrum Security Council’s approved technical solution to transfer 30,765 ETH held by the Kelp DAO attacker to a secure address and freeze it.” The transaction type was ArbitrumUnsignedTxType (EIP-2718 type 0x65/101), which is a system-level transaction that cannot be signed by a regular EOA and can only be injected by the Arbitrum Security Council via ArbOS. This operation did not involve any chain rollback or rewrite of history; functionally, it is a state-level recovery: the attacker’s private key can still sign transactions, but the ETH at that address was transferred by the chain itself. This operation also demonstrates the Security Council’s authority in the “catastrophic emergency” scenario described in Arbitrum's progressive decentralization documentation.