Network suspension follows $100M cross-chain bridge exploit for BNB Chain

By: Micheal Wilson

October 7, 2022 10:33 AM

The BNB Chain team has confirmed rumors of a major exploit on the blockchain and has temporarily disabled all network deposits and withdrawals.

A hack on Binance's cross-chain bridge on October 6 caused the exchange's BNB Chain blockchain to go offline, with attackers stealing about $100 million in digital currency.

The BNB Chain's official Twitter account initially stated that the temporary halt was being implemented because of "irregular activity" on the blockchain, but later clarified that it was being implemented because of a possible exploit. All deposits and withdrawals were halted after Binance announced that the blockchain was "under maintenance."

Twitter users initially speculated that a major hack had occurred on the network, with on-chain analytics indicating that two million (BNB), the chain's native token, had been stolen, a sum worth nearly $600 million.

A BNB Chain developer later updated the community on Reddit, confirming the exploit had occurred and estimating its value at between $100 million and $110 million (with about $7 million currently frozen).

Although "extra BNB" were created as a result of the exploit on the BSC Token Hub, BNB Chain has assured its users that their funds are secure and the issue is being investigated.

Before the official announcements were made, Twitter users conducted preliminary on-chain analysis showing that the attacker claimed a million BNB reward through the token hub and deposited the remainder into the decentralized finance (DeFi) lending platform Venus Protocol.

The BNB Chain was halted after the hackers borrowed $150 million worth of stablecoins from USD Coin (USDC) and Binance USD (BUSD) through cross-chain bridges and traded them for Ether (ETH), Phantom (PHM) tokens, and Polygon (MATIC).

The hacker stole another million Binance Coins (BNB) and deposited them into Stargate Protocol, another cross-chain bridge service.

According to Vesper Finance's strategy lead Zane Huffman, the attacker stole around $100 million from an initial exploit of nearly $600 million, a figure later provided by Zhao.

Huffman also noted that the attacker has digital assets worth more than $400 million frozen on the BNB Chain, with additional funds possibly stuck in cross-chain bridges on the BNB blockchain.

The exploited address has also been blacklisted by Tether, a stablecoin provider.