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Update Nov. 27, 9:23 am UTC: This article has been updated to include comments from Trezor CEO Matej Zak.
South Korea’s biggest crypto exchange, Upbit, temporarily froze deposits and withdrawals on Thursday after detecting about $36 million in unauthorized outflows from a Solana-network hot wallet.&nbsp;
In an announcement, the exchange <a href="https://upbit.com/service_center/notice?id=5800&amp;view=share" rel="noopener noreferrer nofollow" target="_blank">said</a> the suspicious transfers were flagged around 4:42 am local time (7:42 pm UTC), prompting a shutdown of transfer services and a full security review of its supported crypto assets.&nbsp;
Upbit confirmed that the compromise was isolated to its hot wallet, highlighting that cold-wallet reserves remained untouched. The exchange moved its remaining assets into cold storage and initiated onchain freezing attempts.
The incident put fresh scrutiny on Dunamu, which had just <a href="https://cointelegraph.com/news/naver-financial-dunamu-upbit-acquisition-stablecoin" rel="noopener noreferrer nofollow">announced a $10 billion acquisition deal</a> with fintech giant Naver. It also revived memories of Upbit’s 2019 security breach, when the exchange <a href="https://cointelegraph.com/news/upbit-hack-lazarus-south-korea-police" rel="noopener noreferrer nofollow">lost nearly $50 million</a> in an attack orchestrated by the North Korean hacking group, Lazarus.
<blockquote class="twitter-tweet">
 🚨 ALERT: Upbit suspends deposits and withdrawals after $38.5M abnormal outflow on Solana network, reporting the assets were transferred to unknown wallet on Nov 27. Upbit confirms it will cover all losses. <a href="https://t.co/28Eu61s1Tf" rel="noopener noreferrer nofollow">pic.twitter.com/28Eu61s1Tf</a>— Cointelegraph (@Cointelegraph) <a href="https://twitter.com/Cointelegraph/status/1993895246254530831?ref_src=twsrc%5Etfw" rel="noopener noreferrer nofollow">November 27, 2025</a>
</blockquote>
<h2 id="upbit-to-reimburse-user-funds-lost-in-the-breach">Upbit to reimburse user funds lost in the breach</h2>
Upbit said it had suspended deposits and withdrawals across the platform as a precaution, a measure that will remain in place until it completes its security review. The freeze is not limited to Solana-based assets, as the company works to secure its systems and assess remaining risks.&nbsp;
Trading on the platform continues to operate normally, allowing users to buy and sell assets within the exchange. However, users cannot move funds on or off the platform while the review is ongoing.&nbsp;
The company also assured users that any balances lost as a result of the security incident will be fully covered by its reserves, emphasizing that no customer assets will be lost due to the breach.&nbsp;
Upbit said no action is required for customers to recover their funds. However, the exchange asked users to stay patient as it conducts a platform-wide audit and works with regulators to finalize the investigation.
According to local reports, financial authorities have <a href="https://www.nocutnews.co.kr/news/6434957" rel="noopener noreferrer nofollow" target="_blank">started</a> on-site inspections to better understand the incident.&nbsp;
While the exchange assured customers that their funds would be returned, it has not revealed a clear timeline.&nbsp;
Cointelegraph reached out to Upbit and Dunamu for comments, but had not received a response by publication.&nbsp;
<h2 id="crypto-exchanges-are-massive-honeypots-for-hackers">Crypto exchanges are “massive honeypots” for hackers</h2>
At the TBD conference, Trezor CEO Matej Zak stated that security issues surrounding crypto exchanges will not be resolved anytime soon.&nbsp;
“Exchanges are obviously massive honeypots for hackers,” Zak said. “And since security is a moving target, this problem is not going away.”
Zak pointed to the increase in crypto assets lost to security incidents in 2025. On July 1, blockchain security company CertiK reported that <a href="https://cointelegraph.com/news/otal-hacks-down-q2-after-record-losses-2025-h1" rel="noopener noreferrer nofollow">about $2.47 billion had been stolen</a> in hacks, scams and exploits in the first half of 2025.
He also pointed to the <a href="https://cointelegraph.com/news/bybit-infini-hack-bug-bounty-program-flaws" rel="noopener noreferrer nofollow">$1.5 billion Bybit hack in March</a>, which is one of the largest crypto hacks recorded.
Related: <a href="https://cointelegraph.com/news/south-korea-stablecoin-framework-stalls-bank-issuance" rel="noopener noreferrer nofollow">South Korea stablecoin framework stalls as regulators split over banks’ role</a>
<h2 id="security-incident-hits-amid-dunamu-s-global-expansion-plans">Security incident hits amid Dunamu’s global expansion plans</h2>
The incident comes amid an important milestone for Upbit, as its parent company, Dunamu, has <a href="https://cointelegraph.com/news/naver-financial-acquires-dunamu-upbit-10b-stock-swap" rel="noopener noreferrer nofollow">struck a $10.3 billion acquisition deal</a> with South Korean search engine platform Naver.&nbsp;
According to a Wednesday filing, Naver Financial will acquire Upbit operator Dunamu in a stock-swap deal valued at 15.1 trillion won (about $10.3 billion). Naver will issue 87.5 million new shares to Dunamu shareholders and will subsequently make Dunamu a wholly owned subsidiary.&nbsp;
In addition to its acquisition plans, Dunamu also <a href="https://cointelegraph.com/news/south-korea-upbit-parent-dunamu-plans-nasdaq-ipo" rel="noopener noreferrer nofollow">plans to launch</a> an initial public offering (IPO) in the United States following the completion of its merger.&nbsp;
Apart from the acquisition and IPO plans, Naver and Dunamu also reportedly <a href="https://www.techinasia.com/news/naver-dunamu-invest-68b-boost-global-fintech-push" rel="noopener noreferrer nofollow" target="_blank">plan</a> to invest nearly $7 billion over the next five years to develop an ecosystem for Web3 technologies and artificial intelligence.&nbsp;
Magazine: <a href="https://cointelegraph.com/magazine/2026-pragmatic-privacy-crypto-canton-zcash-ethereum-foundation/" rel="noopener noreferrer nofollow">2026 is the year of pragmatic privacy in crypto: Canton, Zcash and more</a>

Upbit hit with $36M Solana hot wallet breach day after $10B Naver deal

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