Ill Bloom Weak RNG Flaw Drains $5.2M from 431 Bitcoin Wallets in Coordinated May 27 Sweep

Coinspect traced the Ill Bloom exploit to insufficient entropy during seed phrase generation in older mobile and browser wallets dating to 2018. The firm rebuilt the attack path, enumerated all feasible phrases from the flawed RNG, derived addresses, and matched them against blockchain activity across Bitcoin, Ethereum, Tron, and Polygon. One coordinated operation moved funds from 431 wallets to shared collection addresses within hours, confirming a single actor rather than scattered thefts.

Public data shows 2,114 exposed addresses with on-chain history. Peak reconstructed value reached $12.56 million in 2022 before market drawdown and the May sweep. Hardware wallets and current mainstream implementations remain unaffected, yet the pattern echoes prior entropy failures in Android SecureRandom and early Ethereum key generators where predictable outputs enabled mass extraction.

The secondary $2.1 million USDT theft on June 10 revealed persistent exposure: the same seed controlled funds across chains, and warnings via exchanges arrived too late. Coinspect continues expanding the vulnerable set without new wallet creation, indicating incomplete enumeration of generation paths.

Users must check every address tied to a single seed at illbloom.org. Remaining exposed wallets face ongoing risk as attackers iterate through additional weak paths; no patches exist for already-generated seeds.