The Initial Analysis of the bZx Security Incident
Contents
On Nov 5th, bZX protocol was reported hacked. The attacker drained tokens in the affected smart contracts. After the initial analysis of the attack transactions, we suspect it’s due to the compromised private key of the developer.
Attack process
The process is roughly simple. The privileged function
transferOwnership is invoked to transfer the ownership of affected smart contract to a new one, e.g.,
0x0acc0e5faa09cb1976237c3a9af3d3d4b2f35fa5. Then the new contract owner can transfer all the tokens that have been approved to the smart contract to arbitrary addresses.
Note that, the privileged function
transferOwnership can only be invoked by the current owner of the smart contract. Indeed, we find the caller of this function is
0xb7f72028d9b502dc871c444363a7ac5a52546608, which is the contract creator of the affected smart contract.
We do not know the exact reason why the contract creator transfers the ownership to other addressees. However, we suspect it’s due to the compromised (or leaked) developer private key.
Conclusion
In summary, the security of the …
Attack process
The process is roughly simple. The privileged function
transferOwnership is invoked to transfer the ownership of affected smart contract to a new one, e.g.,
0x0acc0e5faa09cb1976237c3a9af3d3d4b2f35fa5. Then the new contract owner can transfer all the tokens that have been approved to the smart contract to arbitrary addresses.
Note that, the privileged function
transferOwnership can only be invoked by the current owner of the smart contract. Indeed, we find the caller of this function is
0xb7f72028d9b502dc871c444363a7ac5a52546608, which is the contract creator of the affected smart contract.
We do not know the exact reason why the contract creator transfers the ownership to other addressees. However, we suspect it’s due to the compromised (or leaked) developer private key.
Conclusion
In summary, the security of the …
IoC
0acc0e5faa09cb1976237c3a9af3d3d4b2f35fa5
b7f72028d9b502dc871c444363a7ac5a52546608
b7f72028d9b502dc871c444363a7ac5a52546608