TLDR:

Dunamu revised Solana-linked Upbit losses to 30.4 million dollars while covering user exposure from corporate reserves.
Korea’s financial regulator will conduct an inspection of Upbit’s security and withdrawal systems through December 5.
The breach exposed a private key vulnerability tied to transaction patterns visible on Upbit’s on-chain wallet activity.
Upbit suspended deposits and withdrawals while rebuilding its wallet infrastructure and tracking the attacker’s flows.

Upbit’s parent company faced new pressure after a major security breach pushed the exchange to halt deposits and withdrawals. 

Dunamu CEO Oh Gyeong-seok said the incident stemmed from internal security failures that exposed vulnerabilities in Upbit’s wallet structure. The exchange traced abnormal activity to its Solana-associated wallets, prompting an immediate system-wide review. The updated loss figures show the breach affected tens of millions of dollars, with no customer impact.

Upbit Revises Losses After Wallet Breach

Upbit detailed the breach after identifying unusual withdrawals from a Solana-linked wallet early on November 27. The company said it uncovered a weakness that allowed private key estimation through patterns visible on-chain. 

Dunamu attributed the problem to insufficient security controls and began a full rebuild of its wallet framework.

According to Wu Blockchain, Upbit placed the estimated losses at 44.5 billion KRW. The figure included 38.6 billion KRW in user-related exposure, 2.3 billion KRW already frozen, and 5.9 billion KRW in company losses. Dunamu stated that all affected customer funds were compensated from its holdings.

Solana Daily reported updated numbers, noting Solana-related losses now total 30.4 million dollars. 

Investigators traced funds across several wallets while freezing about 1.57 million dollars tied to the breach. The outlet also noted transaction patterns similar to activity linked to past North Korea-associated operations.

Korea’s Financial Supervisory Service plans to conduct an on-site inspection through December 5. 

The review will focus on Upbit’s withdrawal controls and broader security posture. The exchange said it is maintaining its emergency response mode as upgrades continue.

Dunamu Pledges Stronger Security Measures

Dunamu said it is rebuilding core wallet systems to prevent further exposure. 

The work includes a company-wide audit of every security layer supporting Upbit’s infrastructure. The team is also tracking the moved assets and coordinating with agencies investigating the intrusion.

The company stressed its policy that customer protection remains its highest priority. 

Upbit said it will only reopen deposits and withdrawals once stability is verified. The exchange also plans to publish updates as new details become available.

Dunamu acknowledged the breach underscored the need for continuous technical reinforcement. The company said it intends to use the incident as a catalyst for broader improvements. It emphasized rapid communication as it works with regulators and partners.

Upbit is monitoring its external wallet flows while applying freezing measures to identified addresses. The company reiterated that its reserves fully absorbed the user-related losses. Investigators are still tracking remaining funds and assessing the broader impact.

The post Dunamu CEO Apologizes After Upbit Breach Exposes Security Lapses appeared first on Blockonomi.

---

Filed under: Bitcoin - @ November 28, 2025 10:29 am