According to Fairyproof’s security detection system, on December 2, Ankr, a dApp deployed on the BNB chain was attacked.
The attacker (0xf3a465C9fA6663fF50794C698F600Faa4b05c777) very likely compromised the private key of Ankr Deployer(0x2Ffc59d32A524611Bb891cab759112A51f9e33C0), and then upgraded “aBNBc” with a malicious implementation contract (0xd99955B615EF66F9Ee1430B02538a2eA52b14Ce4). The hacker proceeded to start a mint transaction with the hash value of 0xf3a465C9fA6663fF50794C698F600Faa4b05c777 which minted additionally 10,000,000,000,000 aBNBc tokens.
Ankr Deployer then transferred 1.125 BNBs to the hacker. The hacker then exchanged all the aBNBcs to other assets, among which 200 BNBs were sent to Tornado Cash and others were migrated to other blockchains as follows:
- crypto assets worth around US $4.28 million sent to Ethereum
- crypto assets worth around US $760,000 sent to Polygon
An hour later, Ankr Deployer transferred the owner rights of several Ankr contracts to new addresses.
The hacker exploited US $5 million in this incident.