eBTC

Echo deployed the Monad proxy on February 9, 2026. The live contract identifies itself as eBTC with 10 decimals at 0xd691b0afed67f96cec28ab6308cbe5b2c103b7e9. BadgerDAO’s Ethereum eBTC uses 0x661c70333aa1850ccdbae82776bb436a0fcfeefb and a collateralized-debt design. Their shared ticker does not create shared contracts, collateral or holder rights.

Echo describes its broader product as a liquidity layer that locks supported Bitcoin assets and mints unified BTC on destination chains. Its documentation discusses vaults, proof-of-reserve aspirations and an operator path involving validators and submitters. The material reviewed did not provide a Monad eBTC reserve address, custody agreement, bridge mapping or direct redemption procedure sufficient to reconcile this particular contract with underlying BTC.

At 21:21 UTC on May 18, an address controlling the administrator path granted itself MINTER_ROLE, then called mint on the Echo eBTC proxy. MonadScan records 1,000 eBTC moving from the zero address to the attacker without a corresponding collateral transaction. The token contract executed its authority model; the failure was that control of one administrative route was enough to authorize supply.

Only part of the face amount became a realized loss. Reporting based on the transactions says the attacker deposited 45 eBTC into Curvance and borrowed about 11.29 WBTC, later moving the proceeds toward Ethereum. The remaining 955 eBTC could not be treated as $76 million of cash merely because the newly minted units carried a Bitcoin-sized price label.

Echo said it regained the keys, revoked the malicious privileges, burned the attacker’s remaining 955 eBTC, paused Monad cross-chain functions and Aptos bridge operations, and tightened controls. On May 19 the deployer sent an upgradeToAndCall transaction to the proxy. By September 5, MonadScan points the proxy to implementation 0x7d9a6b4c454ee07561f75faC019c026C7c4db55e; that implementation is not published as verified Solidity on the explorer.

The observed runtime exposes separate minter, pauser and upgrader roles and entry points for issuance, burning, pauses and upgrades. Identifying those entry points does not verify every current check or the quality of control. The reviewed materials did not establish all current permission holders, signature thresholds, delays, issuance caps or enforced reserve checks. CoinYQ therefore cannot treat “tightened controls” as proof of a multisig, timelock or hard cap.

Echo’s general materials say unified BTC should be backed one-for-one by accepted Bitcoin assets. For Monad eBTC, the public record reviewed here does not show which asset backs each unit, who holds it, whether reserves are segregated, or which contract burns eBTC and releases the asset. The token itself is transferable and can be burned by authorized flows, but that does not prove a holder can compel one-for-one delivery.

No reviewed Echo document grants eBTC holders equity, protocol revenue, governance votes or legal title to a named reserve pool.

A buyer therefore receives an ERC-20 balance whose Bitcoin value depends on operator-controlled issuance, integrations, liquidity and an incompletely documented redemption route. The May incident is part of the asset’s biography because it exposed that gap in executable form.