Payy Network’s $1.92M Bridge Drain: Two verifyRollup Batches and 682.3 ETH Routed to Tornado Cash

Executive Summary

On 24 September 2026, Payy Network’s Ethereum RollupV1 bridge paid 1,918,792.198148 USDC to the same recipient across two verifyRollup batches. Both calls were submitted by Payy’s usual batch-posting address. The first payment was rapidly moved to a second contract, converted through UniswapX into approximately 683.38 ETH, and split across four wallets.

By 26 September, three relay paths had deposited a transaction-anchored total of 682.3 ETH into the Tornado Cash Router. A fourth branch retained 1 ETH. The later 90,202.820016 USDC payout remained at the primary recipient; its verified genuine-USDC balance was 90,202.821244 USDC at the 28 September cutoff.

Payy’s initial root-cause update ruled out a compromised key, social engineering, and an exploit of its off-chain infrastructure. The company has not yet published the validated technical cause. The call path proves that verifyRollup processed the payouts; it does not by itself prove which verification or authorization invariant failed.

Incident Anchors

Two verifyRollup Batches

The first batch included ordinary-looking withdrawals to other addresses as well as the dominant transfer to the primary recipient. The second batch used the same function, bridge, submitter, and recipient.

Conversion and Initial ETH Split

At 04:22:59 UTC, the primary recipient transferred 1,828,594.895417 USDC to 0xb483B1742aaD0a60a9FC91bb36C5a42dbE3F3D38 in transaction 0xb2fd99c115ad98162149fa1e0e8243050d3009719910e00bff16808a12ca10e7. Public reporting identifies the conversion venue as UniswapX. The subsequent ETH distributions sum to approximately 683.38205 ETH.

Tornado Cash Deposit Paths

On 26 September, three relay wallets deposited 682.3 ETH into the Tornado Cash Router at 0xd90e2f925DA726b50C4Ed8D0Fb90Ad053324F31b. The transactions used the router’s deposit method. The total is calculated from transaction values, not an estimated USD conversion.

No centralized-exchange deposit was identified before the mixer deposits. The router entry breaks deterministic forward tracing; it does not identify the controller of any eventual withdrawal.

Verified Balances and Status

The primary recipient also displays a separate token using the symbol “USDC” at another contract. This report excludes that token and counts only Circle’s Ethereum USDC contract, 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48.

Evidence Assessment

Response Priorities

Conclusion

The strongest forensic conclusion is not merely that Payy’s bridge lost about $1.92 million. The value followed two distinct post-drain states: 90,202.821244 genuine USDC remained at the primary recipient, while nearly all ETH created from the first tranche was split, relayed, and deposited into Tornado Cash less than three days later.

The transaction history supports a deliberate laundering sequence. It does not establish the technical root cause or the identity of the operator. Those questions require Payy’s validated post-mortem, preserved rollup artifacts, and any later mixer-withdrawal correlation.

Sources

Payy incident notice

Payy root-cause update

Unchained

The Crypto Times

iTokenly incident registry

Ethereum records: Etherscan and Blockscout

SentinelTX case: b92968a7-ee47-4f17-a260-1e5ebfc16a09