Signs of movements of up to $5.57 billion (about 7.5 trillion won) in crypto on the world’s largest cryptocurrency exchange Binance have raised the possibility of a large-scale hack. Stablecoin issuers Tether and Circle froze related assets. Binance is checking whether there was a security incident.

On Oct. 30, blockchain media outlets and others said at least $5.57 billion in crypto moved from Ethereum, Bitcoin and Tron wallets linked to Binance. About $3.51 billion (about 4.71 trillion won) moved on the Ethereum network, along with about $1.44 billion (about 1.93 trillion won) equivalent to 18,270 bitcoin, and about $630 million (about 845 billion won) on Tron. The amount is an estimate based on on-chain data, and the actual size of any theft has not been confirmed.

Blockchain analytics firm Arkham Intelligence tallied assets held by wallets classified as “Binance-Hacker-1029” at about $5.84 billion (about 7.83 trillion won). It said this is the assessed value of assets held in tracked wallets and should be distinguished from confirmed losses.

As a possible attack route, it was suggested that the delegated-authority function of EIP-7702, an Ethereum Improvement Proposal, may have been abused. Addresses believed to be involved in the attack were analysed as having received funds through Tornado Cash and then delegated authority to a Binance hot wallet. About 3 minutes later, 167,464 ETH and 63 tokens moved from the wallet to new addresses. How the attacker obtained the necessary signatures has not yet been confirmed.

Stablecoin issuers also moved to freeze funds. Tether froze about 975.1 million USDT at related addresses, and Circle froze about 823.0 million USDC at the same addresses. The combined amount frozen was about $1.8 billion (about 2.41 trillion won).

Separately, Tether CEO Paolo Ardoino (파올로 아르도이노) said it froze more than $1.57 billion (about 2 trillion won) in USDT related to the incident, and Circle CEO Jeremy Allaire (제러미 얼레어) announced it froze more than $800 million (about 1 trillion won) in USDC in cooperation with investigative authorities. The figures announced by each issuer and on-chain tallies of specific recipient wallets cover different scopes.

Binance said it is aware of potential security issues and is investigating, adding it has not yet confirmed any impact on user funds. A Binance spokesperson said it temporarily suspended withdrawals on several networks as a precaution. Binance co-founder Changpeng Zhao (창펑 자오) said it appears to be a hack but expects user funds will be fully protected. Binance also urged users to watch out for unofficial links and messages and requests for account information.

Markets were also affected. Bitcoin fell below $79,000 and Binance’s BNB token slid about 7 percent. Privacy-focused cryptocurrency Monero (XMR) rose about 6 percent.

If the incident is ultimately confirmed as a hack, it could become the largest crypto theft on record, surpassing the roughly $1.5 billion (about 2 trillion won) Bybit hack in February 2025. Binance’s final findings, the actual scale of damage and whether additional funds will be frozen or recovered have not yet been confirmed.