Key facts
- South Korean law already requires exchanges to hold at least 80% of users' crypto assets in cold storage.
- Upbit's cold wallet ratio was 99.17% at the end of September, per Financial Supervisory Service data cited by local media.
- Bithumb reported 94.76% and Coinone 85%, the same data showed.
- Digital X, formerly Korbit, reported 82.79% and GOPAX 80.54%.
- The FSC said it reviewed exchanges' IT access controls, withdrawal approval and signing procedures, and administrator privileges.
- Binance has said the vast majority of users' assets are held in cold storage.
South Korea's Financial Services Commission said on Monday that it urged domestic crypto exchanges to raise the share of assets kept in offline cold wallets, following the roughly $6.3 billion attack on Binance's internet-connected hot wallets the previous week.
The FSC said it convened an emergency meeting with the Financial Supervisory Service, the Financial Security Institute, the Digital Asset eXchange Alliance (DAXA) and major crypto service providers to assess the Binance hack's effect on South Korea's market and to review exchanges' security arrangements. It said it examined IT access controls, wallet withdrawal approval and signing procedures, and administrator privileges.
Blockchain intelligence firm TRM Labs said attackers moved most of the funds in about 20 minutes. Binance has said the vast majority of users' assets are held in cold storage.
South Korean law already requires exchanges to hold at least 80% of users' crypto assets in cold storage, though holdings vary. At the end of September, Upbit's cold wallet ratio was 99.17%, Bithumb's 94.76% and Coinone's 85%, according to Financial Supervisory Service data cited by local media. Digital X, formerly Korbit, reported 82.79% and GOPAX 80.54%.
The FSC also urged providers to monitor deposits and withdrawals continuously, add incident response personnel, report unusual access attempts promptly and set aside additional reserves. It said it would keep working with agencies and the industry to prevent further attacks and limit potential damage.
Separately, the Bank of Korea is surveying 18 banks and 13 brokerages about their exposure to crypto-related risks, including exchange hacks and prolonged market downturns. The central bank's review began before the Binance attack.