THORChain (2026) — Crypto Hack
Not RecoveredA flaw in THORChain's GG20 threshold signature scheme let an attacker gradually reconstruct vault keys and drain $10.8M across four chains.
Summary
A flaw in THORChain's GG20 threshold signature scheme let an attacker gradually reconstruct vault keys and drain $10.8M across four chains.
How It Was Compromised — Protocol Exploit via Vulnerability in GG20 threshold signature scheme (TSS) implementation. Attacker gradually leaked vault key material over time, eventually reconstructing the private key of one of six Asgard vaults. Stolen: 36.75 BTC (~$3M) + ~$7M in tokens across BNB Chain, Ethereum and Base. Affected 12,847 wallets across 4 chains. Exploit was pre-planned — attacker routed funds through Monero, Hyperliquid, and Arbitrum weeks before the attack. Chainalysis traced a 43-minute fingerprint linking pre-attack wallets to the exploit wallet.
On May 15 2026, THORChain suffered a $10.8M exploit when an attacker exploited a vulnerability in the GG20 Threshold Signature Scheme (TSS) implementation used by THORChain's Asgard vaults. By gradually leaking vault key material over an extended period, the attacker eventually reconstructed the private key for one of six Asgard vaults, enabling them to authorize unauthorized outbound transactions. A recently churned node was identified as linked to the breach. The exploit drained 36.75 BTC (approximately $3M) plus approximately $7.8M in tokens across BNB Chain, Ethereum, and Base, affecting 12,847 wallets. Cross-chain DeFi operations were halted for 13 hours during investigation. THORChain launched a recovery portal on May 15 with a 21-day claim window (deadline June 4 2026) and a treasury-funded refund pool equal to losses. Chainalysis and Outrider Analytics are conducting ongoing forensics.
Fund Flow & Laundering Analysis
The operation showed clear pre-planning. Chainalysis traced a 43-minute fingerprint linking pre-attack wallets to the exploit wallet, showing the attacker moved funds through Monero, Hyperliquid, and Arbitrum before the attack was executed. Post-attack, stolen funds were routed back to Monero through a Hyperliquid-to-Monero privacy bridge, exploiting Monero's privacy features to obfuscate the trail. The use of privacy chains and pre-staging of funds indicates a sophisticated, state-level actor.