Centralized cryptocurrency exchange DMM finds itself grappling with a substantial setback after losing over $305 million worth of Bitcoin (BTC) due to a private key breach on May 30.

Confirming the hack on its website, DMM assured users that all deposited funds would be fully secured, but temporary suspensions were placed on withdrawals, new account registrations, spot buy orders, and leveraged transactions. However, pre-existing limit orders remain unaffected by the halt.

News of the breach began circulating within the crypto community via social media platform X following a notification from analytics platform Whale Alert. The alert flagged a significant transfer of 4,502.9 BTC, valued at $305 million, from an unidentified wallet to another. While initially labeled as originating from an "unknown" source, DMM later acknowledged the loss of precisely 4,502 BTC in the attack, indicating a probable correlation with the flagged transaction.

DMM swiftly initiated damage control measures, assuring users of steps taken to prevent further unauthorized disclosures. Plans are underway to compensate affected users by procuring an equivalent amount of BTC, with assistance from affiliated group entities. Users are urged to remain vigilant for updates, as services are expected to resume once security measures are reinforced.

Established in January 2018, DMM Exchange operates under the umbrella of the e-commerce giant DMM Group, which also encompasses a cryptocurrency mining venture. The incident adds to a series of security breaches and fraudulent activities plaguing the crypto exchange landscape, underlining persistent vulnerabilities within the sector.

Notable recent cases include Poloniex's loss of over $100 million due to a private key compromise in November and GDAC's $14 million losses from a similar attack in April 2023.