Cysic has suspended its cross-chain bridge after an attacker created 10 million unauthorized CYS tokens on BNB Chain and converted part of the supply into assets moved toward Ethereum.
TL;DR: On-chain analysis traced the sale of about 7.2 million CYS and the receipt of 306.6 ETH, valued at roughly $727,000 at the time. The bridge was stopped while the incident was investigated.
The mechanics of the attack illustrate why bridges remain an awkward security problem. A token minted on one network is supposed to correspond to an authorized event elsewhere. When that verification breaks, an attacker can create assets with no legitimate backing and sell them into whatever liquidity is available before a project can respond.
Blockchain records reviewed in the incident showed the attacker exchanging the newly minted tokens through decentralized venues and routing proceeds across chains. Cysic took action to suspend the bridge and block an address, but intervention came after a substantial portion of the unauthorized issuance had already been traded.
The immediate damage is not limited to the amount ultimately received in ETH. New tokens entering the market can also pressure CYS’s price, expose liquidity providers to losses and leave honest holders uncertain about which balances are valid. Recovery becomes harder as swaps and bridges split proceeds across multiple destinations.
Cysic will need to account for the failure in its message-verification process and explain any corrective action before normal operations can safely resume. Users should distinguish between the bridge’s security and the wider network’s functioning rather than assuming that every component suffered the same compromise.
The incident is another example of a technical shortcut in cross-chain accounting becoming a market-wide event in minutes.
Written by the News Desk and edited by Samuel Rae.
