Security firm Coinspect has identified a significant vulnerability affecting thousands of cryptocurrency wallets across multiple blockchains. The company named the issue 'Ill Bloom', which stems from weak randomness during wallet creation that has exposed wallets since 2018. According to Coinspect's analysis, the flaw allows attackers to guess private keys more easily than they should be, potentially draining funds from vulnerable accounts. The issue affects wallets created on Bitcoin, Ethereum, Polygon, Rootstock, Tron and Solana blockchains, with the problem traced to weak randomness in recovery phrase generation in some software wallets using an insecure pseudorandom number generator when creating seed phrases. As Coinspect states, "If funds recently moved without your permission, this vulnerability may be why." The researchers reproduced the attack end-to-end, deriving every address the weak phrases could produce and matching them against funded wallets on public blockchains.
According to Coinspect's analysis, the monitored set contains 2,114 funded addresses across Bitcoin, Ethereum, Tron, Rootstock, and Polygon blockchains. On May 27, attackers drained accounts by sending balances to a handful of shared collector addresses within hours. Bitcoin absorbed the biggest hit at $2.57 million, with one account alone losing over $1.1 million. The firm calls the $3.1 million figure a lower bound because new affected accounts keep surfacing. Historically, the exposed set held up to $12.56 million at its April 2022 peak. The sweep adds to heavy crypto theft losses this year, which topped $400 million in January alone. Coinspect notes that compromised keys drain value fast, as recent private key breaches at Humanity Protocol showed.
According to Coinspect's research, hardware wallet users appear unaffected so far, while users of lesser-known mobile wallets face higher risk. The firm stated that current evidence tells us that users that generated their seed with a hardware wallet are not affected, and further research indicates that most current software wallets are also not vulnerable. However, users who created seeds in less widely used mobile software wallets face the strongest risk, as they may have used poor number generators when creating seed phrases. The vulnerability is more common in lesser-known mobile software wallets, making users of these platforms the primary target for potential attacks. Coinspect emphasizes that "the strongest candidates are users who generated their seed in less widely used mobile software wallets." Earlier this year, Binance issued a critical iOS alert for mobile users, highlighting ongoing concerns about mobile wallet security.
Security firm SlowMist has confirmed it is "closely monitoring the Ill Bloom wallet weak randomness risk alert" from Coinspect and advising users to check older wallet addresses. SlowMist's Chief Information Security Officer, 23pds, has emphasized the ongoing risk of weak randomness in wallet generation and advised users to verify their mnemonic phrases. Coinspect has released a wallet-checking tool so users can test whether their addresses may be exposed, though the company has not published full exploit details because the risk remains active. Users with exposed wallets are advised to consider moving funds to newly generated wallets created through trusted software or hardware wallets, and avoid reusing old seed phrases that may have weak randomness. The firm cautioned users to "run the checking tool and review recent transactions for any unauthorized moves," while noting that the company is withholding technical details of the active exploit to limit further harm. SlowMist posted to X on Monday confirming their monitoring of the alert.
The Ill Bloom vulnerability fits a pattern of wallet security issues, including previous weaknesses in seed entropy. In 2023, Ledger's security team discovered that wallet seeds generated by the Trust Wallet browser extension were vulnerable to brute-force attacks, with the flaw residing in the wallet's entropy generation for new addresses which limited the total possible mnemonic combinations to roughly four billion and could allow a motivated attacker to run an attack in less than a day with just a few GPUs. Trust Wallet patched the bug before any funds were stolen. Additionally, a separate 2023 flaw in a wallet implementation led to $900,000 in crypto being stolen through private-key brute forcing. The current Ill Bloom flaw demonstrates how device security and wallet security can overlap, with vulnerabilities persisting for years before detection. Coinspect is now urging wallet providers to implement a weak mnemonic detection feature to help prevent future exploitation of this ongoing threat. Users are advised to create a brand-new crypto wallet and migrate funds to its addresses, as importing old phrases into another app leaves money exposed. Coinspect stressed that "We will never ask for seed phrases, private keys, signatures, or approvals, or ask users to send funds to 'recover' or protect a wallet."
