Coinsbuy Says Customer Funds Covered After $8 Million Cross-Chain Hack

Crypto exchange Coinsbuy lost roughly $8.07 million in a coordinated attack across TRON and Ethereum on Aug. 9, according to onchain data reviewed by blockchain security researchers and reported by CoinDesk. The activity linked what first appeared to be separate drains into a single operation spanning two blockchains.

The incident matters because it shows how attackers can move quickly across chains and services, complicating response efforts for exchanges and investigators. It also adds to a costly year for crypto security, with CoinDesk reporting that nearly $972 million had already been stolen across the sector through late July.

According to the report, the attacker began with a 5 USDT transaction, then drained eight TRON wallets of 6.04 million USDT in about an hour. At the same time, three Ethereum wallets were emptied of 1.89 million USDT and 77 ETH, with the assets swapped to ETH through 1inch using a wallet created the same day.

Onchain records tied the TRON and Ethereum activity through the cross-chain swapper Bridgers, whose Ethereum payout contract sent funds into the Ethereum swap wallet. About 79% of the stolen funds were routed through FixedFloat using roughly 50 single-use addresses, while ChangeNOW froze a six-figure amount after contact from Specter Investigations. Around 282 ETH, valued in the report at about $542,000, remained unmoved across five addresses.

Coinsbuy refilled the drained wallets within 24 hours to within 0.05% of their pre-attack balances, a pattern researchers said suggests the exchange did not believe private keys were compromised. Coinsbuy told CoinDesk the incident had been contained, that affected amounts were covered in full from company reserves, and that no client had borne a loss. The company said the platform was stable and operating normally while the investigation continued.