Polymarket temporarily suspends trading on international platform due to security incident

Polymarket suspended trading on its international platform on Thursday following a security incident that compromised a third-party provider. The prediction market operator paused operations for approximately one hour before resuming services in the afternoon. The company stated it acted out of an abundance of caution after identifying and resolving the issue affecting Polymarket.com. In a statement posted on social media, the firm pledged to fully reimburse any traders who suffered losses during the disruption. The incident appears to have originated from the United Kingdom, leading Polymarket to refer the matter to British law enforcement agencies. Reports link the breach to DebugBear, a UK-based firm providing website performance monitoring tools. A person familiar with the details, speaking anonymously to discuss the evolving security situation, indicated that hackers accessed funds through software supplied by DebugBear. DebugBear’s own website was inaccessible on Thursday afternoon. The company acknowledged on social media that it was impacted by an ongoing security incident. It advised clients utilizing its products to remove specific embed codes from their sites. DebugBear did not immediately respond to requests for comment regarding the scope of the breach. Unconfirmed reports emerged from users on Polymarket’s Discord channel claiming their digital wallets had been drained. While the platform did not officially confirm individual financial losses, it reiterated that anyone impacted would be made whole. Crypto news outlet The Block reported that approximately $2.65 million in cryptocurrency was siphoned from user wallets, citing data from blockchain analysis group Arkham. A Polymarket representative declined to verify that specific figure or provide further details on the precise nature of the attack. Trading on the international site halted around 2 p.m. Eastern Time and restarted at 3 p.m. Eastern Time. The company noted that its US-based platform did not appear to be affected by the breach. This incident highlights a growing trend where malicious actors target third-party vendors to gain entry into major platforms. Such supply chain attacks have become a common vector for compromising large-scale websites and applications. Polymarket operates as a high-volume prediction market, processing roughly $200 million in trading activity daily. The platform recently attracted significant investment attention. In September, the company was valued at $21 billion after a group of investors led by Donald Trump Jr. committed $1 billion to the venture. The firm currently faces regulatory scrutiny alongside rival Kalshi. An intense legal battle exists between US states and the federal government over which entity holds jurisdiction to regulate prediction market betting. The immediate focus remains on restoring trust among users and determining the full extent of the compromise. Polymarket confirmed the technical fix for the international platform but withheld specifics on how long the vulnerability remained active before detection. The involvement of a third-party analytics tool underscores the complexity of securing modern digital infrastructure. Users continue to monitor their accounts while the company executes its reimbursement promises. Law enforcement investigations in the UK are underway to trace the origin of the intrusion. The industry watches closely as similar vulnerabilities could affect other platforms relying on external monitoring services. The resolution of this case may influence future security standards for prediction markets globally. For now, the primary concern is ensuring that all affected parties receive the compensation promised by the platform operators.