Beepre reports that security firm GoPlus released a vulnerability analysis on social media stating that user assets were stolen from the international site of the prediction market platform Polymarket. The RUM script from the third-party performance monitoring service DebugBear was compromised via supply chain contamination, resulting in malicious code being delivered to users' pages and exploited to abuse their transaction and signing permissions.
On-chain analysis shows that the main attack path involved 710 DepositWallets and 731 addresses, resulting in losses of approximately $2.71 million; the number of addresses does not represent the number of actual users. Polymarket subsequently confirmed that the issue has been resolved and services have been restored, and pledged full compensation to affected traders. The actual compensation progress will be subject to official announcements going forward.