Exploit (crypto hack)

In crypto news, an exploit usually means that someone found a weakness and used it to drain value. The flaw can sit in a smart contract's code, in the economic design of a protocol, in a price oracle, in a bridge's validation logic or in the way private keys are managed. Because transactions are public and final, a single exploit can move hundreds of millions of dollars in minutes.

Notable cases include the 2016 attack on The DAO, the 2021 Poly Network exploit of around 600 million dollars, which the attacker later returned, and the February 2025 theft of roughly 1.5 billion dollars from the Bybit exchange, attributed by the FBI to North Korean hackers. After an attack, protocols often pause contracts, trace the funds and offer the attacker a bounty to return most of them.

Audits, bug bounties, spending limits and monitoring reduce the risk but cannot remove it. Users exposed to a protocol can lose funds even if they did nothing wrong.