Prediction market platform Polymarket temporarily suspended trading operations after hackers compromised a third-party service to distribute malicious JavaScript designed to drain users' cryptocurrency wallets, according to Bleeping Computer.
The security incident involved the unauthorized modification of a script provided by DebugBear, a performance-monitoring service used by the platform. By injecting malicious code into the service, attackers gained the ability to hijack authenticated user sessions. The malware was designed to liquidate prediction-market positions and transfer cryptocurrency assets directly to an attacker-controlled wallet. Blockchain analysis revealed that approximately $2.5 million in assets were moved to wallets linked to the breach. Polymarket identified the issue on Thursday, placing its exchange into a temporary halt while engineers removed the compromised integration.
The platform resumed normal operations approximately one hour after the initial suspension. While the company has not disclosed the total number of affected users, it has committed to fully reimbursing those impacted by the unauthorized transactions. DebugBear has since advised all customers to remove its monitoring code while it investigates the extent of the compromise. This event highlights the significant risks associated with third-party supply chain dependencies in modern web applications, where external scripts can be weaponized to bypass internal security controls and target end-user funds directly.
Source: Bleeping Computer
