Regulator opens sanctions against Dunamu for Upbit hack

South Korea's Financial Supervisory Service has initiated formal sanctions proceedings against Dunamu, the operator of the Upbit cryptocurrency exchange, following a major security breach in November 2025. The regulator delivered an inspection opinion letter to the company on July 19, 2026, marking the start of a process that could lead to penalties, though significant legal uncertainties remain.

The incident occurred on November 27, 2025, beginning at 4:42 a.m. Korea Standard Time. The intrusion lasted approximately 54 minutes and specifically targeted Solana-based digital assets. Initial loss estimates were around $36 million, but authorities have since revised the figure to 44.5 billion won, equivalent to roughly $32 million. The exchange faced public criticism for its disclosure timeline, as it did not publicly acknowledge the breach until late that evening, after a scheduled corporate meeting involving Naver Financial had concluded.

Upon detecting the suspicious transactions, Upbit immediately transferred assets to offline cold storage and suspended all deposit and withdrawal functions. The exchange committed to fully reimbursing affected customers using its own corporate...