Summary
On September 20, 2022, market maker Wintermute lost about $160M from its DeFi operations due to the Profanity vanity-address vulnerability (CVE-2022-40769). Wintermute's admin EOA used an address generated by the Profanity tool, which seeded its key generation with only a 32-bit value fed through a Mersenne Twister PRNG, collapsing the effective keyspace from 2^256 to about 2^32 (~4 billion) and making the private key brute-forceable. Attackers precomputed candidate keys and reversed Profanity's deterministic iteration to reconstruct the private key of the vanity admin address, then used its retained admin/owner privilege over Wintermute's vault contract to drain it. A contributing error was Wintermute's failure to retire the Profanity-generated admin account after the public 1inch disclosure on September 15, 2022 (five days before the hack) warned that such addresses were unsafe. The attacker was never identified and a 10% bounty offer to return the funds was refused.
How to avoid it in your code
- Never derive keys from weak or low-entropy seeds; use audited CSPRNGs with full 256-bit entropy.
- Avoid vanity-address generators; immediately retire any address from a known-vulnerable tool like Profanity.
- Hold admin/owner privileges in MPC/HSM-backed multisig rather than a single EOA.
- Rotate privileged keys and remove stale admin addresses promptly after any disclosure.
- Monitor vault admin actions and alert on owner/privilege use from a deprecated address.
References
- https://www.halborn.com/blog/post/explained-the-wintermute-hack-september-2022
- https://www.theblock.co/post/171192/experts-blame-a-vanity-address-bug-for-wintermutes-160-million-hack
- https://www.bankinfosecurity.com/wintermute-ceo-renews-plea-for-hacker-to-return-stolen-funds-a-20124
- https://medium.com/amber-group/exploiting-the-profanity-flaw-e986576de7ab
- https://github.com/advisories/GHSA-9q2f-7hm7-62h6
Related vulnerabilities
All Web3 →- CRITICALWEB3-ATOMICWALLET-2023
On June 3, 2023, users of Atomic Wallet, a non-custodial cryptocurrency wallet, lost over $100M (an early Elliptic estimate of ~$35M was later revised upward) across at least 5,500 accounts. Atomic Wallet never published a root cause, so the exact technical mechanism remains officially undisclosed and disputed; leading unconfirmed theories, consistent with a compromise of key generation or key exfiltration, include weak entropy or insufficient randomness in seed generation creating a brute-forceable keyspace, private keys or seeds being exfiltrated to a server (for example via logging), a supply-chain compromise of the app build, or fault attacks on the signing algorithm. Blockchain forensics firm Elliptic attributed the heist to North Korea's Lazarus Group with high confidence on June 6, 2023, based on laundering through the Sinbad mixer and Garantex and, most tellingly, stolen funds flowing into wallets already holding proceeds of prior Lazarus hacks; the FBI later supported this. Only a small portion (over $1M) was frozen and the bulk was not recovered. A class action (Colorado federal court) was later dismissed.
- CRITICALWEB3-KELPDAO-LAYERZERO-2026
On April 18, 2026, North Korea's Lazarus Group drained about 116,500 rsETH (roughly $292 million) from KelpDAO's LayerZero-based bridge, the largest DeFi exploit of the year. No smart contract was broken; the contracts did exactly what they were written to do. The attack was against the bridge's off-chain verification. rsETH's LayerZero channel was configured to trust a single verifier (a 1-of-1 DVN), so the attackers compromised LayerZero's internal RPC nodes, knocked out the honest external node with a denial-of-service flood, and forced that single verifier to attest to a cross-chain message that never really happened. The Ethereum side then released unbacked rsETH from escrow, leaving wrapped rsETH stranded across more than twenty chains and triggering a bank-run across DeFi.
- HIGHWEB3-FRONTEND-DNS-HIJACK-2022
A frontend hijack leaves the on-chain contracts untouched but replaces the Web2 surface serving the dApp UI with a wallet-drainer clone, so no Solidity audit can catch it. The recurring pattern: attackers take over the domain registrar or DNS provider account (or a CDN/tag-manager account), repoint the domain to a cloned site, and prompt visitors to sign malicious token approvals, EIP-2612 permit signatures, or transfers. Curve Finance was hit twice: on August 9-10, 2022 its curve.fi domain was DNS-hijacked via a compromised nameserver and drained ~$570K in USDC/DAI; and again around May 12, 2025 at the registrar level, after which Curve permanently migrated to curve.finance and announced an ENS move (Convex Finance and Resupply, which depend on Curve's data feeds, suffered dependency-driven outages but were not themselves compromised). In July 2024 a mass wave hit DeFi domains registered through Squarespace, whose forced migration off Google Domains stripped 2FA: Compound's frontend redirected to an Inferno Drainer clone and 100+ protocols were exposed (Celer blocked its takeover via domain monitoring). Ambient Finance's domain was hijacked through stolen registrar credentials on October 17, 2024. Most recently, on April 14, 2026 attackers used forged identity documents to social-engineer the registrar into handing over DNS control of CoW Swap's swap.cow.fi and cow.fi domains, redirecting users to a pixel-perfect drainer clone for about 90 minutes; over $1M was taken in roughly three hours, including 219 ETH (~$750K) from a single wallet, while CoW's contracts, backend APIs, and solver network were untouched. The same bucket includes CDN-account injections (KyberSwap's September 2022 Cloudflare/Google Tag Manager compromise, ~$265K) and BGP route hijacks that swap signed bundles for drainer code.
- CRITICALWEB3-DRIFT-2026
On 1 April 2026, attackers drained about $285 million from Drift, the largest perpetual-futures exchange on Solana, in roughly twelve minutes, more than half of everything the protocol held. There was no smart-contract bug. The contracts worked exactly as written. The attackers, later tied to North Korea's Lazarus operations, spent months socially engineering the people with privileged access, then abused a Solana feature called durable nonces to get the protocol's multisig signers to approve, in advance and without realising it, the transactions that handed over control. Once they had admin rights they whitelisted a worthless token as collateral, deposited a pile of it, and borrowed out the real money. It is the case that proves the modern crypto heist is an operations and social-engineering problem, not a Solidity one.
- CRITICALWEB3-BUNNI-2025
On September 2, 2025 Bunni, a liquidity manager built on Uniswap v4, was drained of roughly $8.4 million across Ethereum and Unichain (USDC, USDT, and weETH/ETH) through a rounding error in its withdrawal accounting amplified by flash loans. Bunni's Liquidity Distribution Function (LDF) tracks an 'idle balance' that is rebalanced on every swap, and the withdraw path rounded that balance in the wrong direction under specific conditions. The attacker flash-borrowed millions in USDT and executed a precisely sized sequence of swaps that pushed the pool's spot price back and forth across tick boundaries, triggering the faulty rounding repeatedly; each cycle let them withdraw more tokens than they burned in liquidity (in the USDC/USDT pool the idle balance fell 85.7% while liquidity fell only 84.4%, and that gap was the leak). The bug was application-specific accounting math, not an oracle or price-feed flaw. Unable to fund a secure relaunch, the Bunni team announced on October 23, 2025 that it was permanently shutting down, leaving withdrawals open and relicensing v2 from BUSL to MIT.
- CRITICALWEB3-CETUS-SUI-2025
On 22 May 2025, Cetus Protocol, the largest decentralized exchange on the Sui blockchain, was drained of about $223 million in the time it takes to read this sentence. The attacker did not steal a key or trick a signer. They found a single wrong constant in an overflow check, buried not in Cetus's own code but in a shared open-source math library, integer-mate, that Cetus and several other Sui projects all depended on. With a one-token deposit and a flash loan, they convinced the protocol that a position worth almost nothing was worth a fortune, then withdrew the real reserves. It is the cleanest modern example of a vulnerability in a dependency draining the protocols built on top of it, and the second largest crypto theft of 2025 after Bybit.