South Korean crypto exchanges have been required to store at least 80% of their customers' crypto assets in cold wallets, but regulatory authorities are still urging for an even higher increase in this ratio.

The Financial Services Commission of South Korea ( FSC ) stated that following Binance's attack of $6.3 billion last week, the commission has urged domestic cryptocurrency exchanges to increase the proportion of assets stored in cold wallets.

FSC issued a statement on Monday stating that it had held emergency meetings with the Financial Supervisory Service, the Financial Security Research Institute, the Digital Asset Exchange Alliance ( DAXA ), and major cryptocurrency service providers to assess the impact of the Binance hack incident on South Korea's cryptocurrency market and to review the security measures of the exchanges.

FSC indicates that the meeting reviewed the exchange's IT access control, wallet withdrawal approval and signing procedures, as well as administrator permissions. Regulators also urged service providers to increase the proportion of assets stored in offline cold wallets.

According to blockchain intelligence company TRM Labs, attackers stole approximately $6.3 billion from Binance’s hot wallets last week and transferred most of the funds within about 20 minutes. Binance stated that the vast majority of users’ assets are stored in cold storage.

South Korean law already requires exchanges to store at least 80% of users' encrypted assets in cold storage, however, there is a significant variation in the proportion of cold wallet holdings among the major exchanges in Korea.

According to data cited by local media from the Financial Supervision Agency, as of the end of September, the cold wallet ratio for Upbit was 99.17%, for Bithumb it was 94.76%, and for Coinone it was 85%. Previously known as Korbit, the ratios for Digital X and GOPAX were 82.79% and 80.54% respectively.

FSC also urges service providers to continuously monitor deposits and withdrawals, to staff with more personnel for incident response, and to report and share information on attempted abnormal accesses in a timely manner.

Regulatory authorities also require operators to set aside additional reserves and implement other security measures that can be implemented immediately to prevent similar vulnerabilities from occurring again. FSC indicates that cooperation will continue with relevant institutions and industries to prevent further attacks and limit potential losses.

Cointelegraph has contacted Upbit, Bithumb, Coinone, Digital X, and GOPAX to seek their comments on this matter.

At the time of the warning regarding FSC, the Bank of Korea was also conducting separate investigations into the exposure of 18 banks and 13 securities firms to crypto-related risks, including major exchanges being hacked and the long-term market downturn. The central bank's review had already begun prior to the attack on Binance.