Analysis of CryptoJS PRNG Defect Leading to Predictable Crypto Wallet Seeds (Ill Bloom Vulnerability)

Vulnerability Overview In May 2026, Coinspect identified a wallet generation vulnerability affecting users across multiple networks. This vulnerability had existed for over ten years and was already being exploited by attackers during the investigation. The root cause lies in a flaw within the random number generation function of the CryptoJS library, which allows for the prediction of generated recovery phrases. Impact Scope Time Span: The vulnerability has existed for over ten years. Affected Scope: Wallet applications across multiple networks are impacted. Specific Impact: Attackers can generate candidate recovery phrases and, by cross-referencing them with blockchain data, identify the actual recovery phrases in use, thereby gaining access to users' wallets. Remediation Technical Disclosure: Coinspect established a dedicated research website (illbloom.org) detailing the technical disclosure, investigative methods, and findings. Address Checker: Coinspect developed a public address checker to help users verify whether their addresses belong to the set of affected addresses. Collaboration and Notification: Coinspect collaborated with relevant parties to notify affected users and assist them in implementing protective measures. Dependency Path Identification: Affected projects and users are advised to identify vulnerable dependency paths, assess historical exposure, and migrate funds from wallets that rely on insecure random number generation. Key Findings Root Cause: A defect in the random number generation function within the CryptoJS library. Historical Context: Although this vulnerability was patched in 2014, downstream wallet applications continued to use outdated versions. Public Discussion: The vulnerability has been publicly discussed multiple times on GitHub Issues. Relevant Links Technical Disclosure: Ill Bloom Technical Disclosure: The CryptoJS Randomness Vulnerability Identifying Vulnerable Wallets: Identifying the Wallets Behind Vulnerable Recovery Phrases Research Website: illbloom.org Summary Coinspect’s investigation revealed a long-standing vulnerability in the CryptoJS library's random number generation function, which has been exploited by attackers for years. Through technical disclosure, a public address checker, and collaboration with stakeholders, Coinspect has helped affected users and projects implement protective measures. Users and projects are advised to update their dependencies and migrate funds to avoid further losses.

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Analysis of CryptoJS PRNG Defect Leading to Predictable Crypto Wallet Seeds (Ill Bloom Vulnerability)