One week after Axie Infinity was hacked, hackers cracked another NFT game

The publishers of the play-to-earn blockchain-based video game WonderHero were forced to temporarily shut down all of their services as the value of its tokens dropped catastrophically after an unknown hacker minted the game’s tokens and managed to withdraw about $300,000.

WonderHero representatives confirmed a cyberattack on its crosschain bridge, which allows the transfer of cryptocurrency on one blockchain to another. The attacker managed to get a signature and mint 80 million WND (game cryptocurrency).

According to CoinMarketCap, the value of the WonderHero token (WND) dropped by about 50% after the cyberattack.

WonderHero is an anime-inspired mobile RPG game set in the future. The Earth has been contaminated by the waste of a nuclear war, and the last human civilization is moving to live on a huge space station. Players collect characters, weapons, and items, all from NFT. Players must buy or earn WND cryptocurrency to upgrade characters.

The attack comes just a week after hackers managed to steal more than $600 million in cryptocurrency from the cross-chain bridge of another play-to-earn game, Axie Infinity. With the help of hacked private keys, the attackers faked the withdrawal of funds. They exploited a bridge in the Ronin blockchain network that communicates with the Ethereum-based Axie Infinity, seizing control of most of its validator node, which validates and approves transactions.

As ZenGo IS expert Tal Be’ery explained, the hackers were most likely able to gain access to WonderHero’s private key, which allowed them to mint new tokens. It’s impossible to determine how the attackers got their hands on the private key, but there’s no doubt they got it, Be’ery assured.

“How do we know the private key was stolen? In order to add someone as a ‘checker,’ you need a private key to sign the transaction in question,” the expert explained to Motherboard.