On September 15, a blockchain security firm disclosed a vulnerability affecting Profanity, a tool that allowed people to generate "vanity" crypto wallet addresses: addresses containing specified strings of characters. This affected some individuals with vanity addresses, but has also enabled subsequent attacks on projects that used vanity addresses, such as the Wintermute exploit on September 20.
On October 11, the QANX Bridge's deployer wallet was compromised thanks to the vanity address generator bug. Although QAN had not directly used the Profanity project to generate the address, they used a project called vanity-eth-gpu, which had derived its code from Profanity and so inherited the bug. QAN is a layer 1 blockchain that claims to be quantum-resistant.
The thief stole 1.44 billion QANX from QANX's BNB Chain bridge, which they traded for 3,090 BNB (~$837,000) and tumbled through Tornado Cash. One minute later, they drained 1.43 billion QANX from QANX's Ethereum bridge, traded it for 255.4 ETH (~$327,000), and tumbled it as well. In total, $1.16 million was cashed out via Tornado. News of the attack, and the attacker's sell-off, caused the QANX price to plummet by 94%.
The attacker still holds more than 1 million QANX, nominally worth $608,000. However, QAN withdrew liquidity for the project on Uniswap and Pancakeswap, which will make it more difficult for the attacker to sell off their remaining tokens.
This was the second theft affecting the QAN platform this year. In May, an attacker stole 4.4 million QANX, which they traded for 370 ETH (valued at ~$707,000 at the time).