Poly Network Exploit Results in Billions of Nonexistent Tokens
Poly Network, the China-based interoperability platform, was targeted by hackers over the weekend in a major attack that resulted in the creation of billions of tokens out of thin air. It’s the second time in as many years that the cross-chain bridge has been exploited by hackers.
The attacker exploited a vulnerability in Poly Network’s cross-chain bridge tool, allowing them to generate a substantial number of tokens that previously did not exist, as reported by Arhat, the Founder of 3z3 Labs, on Twitter.
Network suspension
The Shanghai-based project team behind Poly Network promptly informed its users on Sunday that its services were temporarily suspended due to the attack. The platform assured its users that it was diligently assessing the extent of the breach and the impact on assets. They emphasized their commitment to safeguarding users’ assets and urged everyone to remain calm.
The hacker, at one point, held nearly $43 billion worth of cryptocurrency in their digital wallet, according to DeBank, a decentralized finance portfolio tracker. This staggering figure was corroborated by PeckShield, a blockchain data and security firm.
Bridge vulnerabilities
Bridges play a crucial role in the Web3 ecosystem, enabling users to transfer assets across different networks. However, they have often been attractive targets for hackers. In this attack on Poly Network, the hackers issued themselves nearly 100 million BNB and $10 billion worth of BUSD, the Binance-branded stablecoin, on the layer-2 network Metis, revealed Colin Wu, a Chinese crypto journalist.
Similarly, on the Heco network, approximately 100 trillion units of the dog-themed meme coin, Shiba Inu, were created. Additionally, a significant number of altcoins were generated on Polygon and Avalanche networks.
Illiquid Metis tokens
Metis clarified that the BNB and BUSD tokens issued on its network by the hackers are effectively worthless since there is no available sell liquidity. Poly Network also locked these tokens, ensuring they cannot be utilized. Arhat of 3z3 Labs acknowledged that the impact of the Poly Network attack was somewhat mitigated by the lack of liquidity, which prevented the hackers from realizing substantial gains on Metis.
However, on other networks like Ethereum, the stolen tokens were exchanged on decentralized exchanges. Arhat estimated that the attacker managed to convert only a small portion of the tokens, amounting to approximately $400,000 worth of crypto, while the remaining tokens lacked liquidity and were essentially worthless.
SlowMist, a blockchain security firm, suggested that the hacker’s total gains were higher. They reported that over $4 million worth of digital assets from the attack had been cashed in, including 1,500 Ethereum worth $3 million and 93 billion SHIB worth $700,000.
Poly Network had previously made headlines in 2021 when it experienced a historic attack, considered the largest exploit in decentralized finance at the time. The project suffered a loss of $600 million as funds were siphoned away from Ethereum, Binance Smart Chain, and Polygon. However, the hacker eventually returned $342 million worth of stolen crypto, and Poly Network took steps to repay affected users.
