Rating:
We were given the challenge text:
I just found this dope smart contract, you just give it a secret and it hides it on the ethereum network.
address: 0x9B0780E30442df1A00C6de19237a43d4404C5237
author: pop_eax
Along with the file alerted.sol.
This time the flag was encrypted in the contract, so we couldn't see it without reversing it (which of course isn't intended). To make a change on the blockchain (to store the secret text), a transaction has to be sent. Knowing this, we can assume that the flag has been sent as input data to the contract. The 5th transaction after the contract creation included the flag. All we have to do to see the flag is convert the hex input to UTF-8, giving us the flag: flag{3v3ryth1ng_1s_BACKD00R3D_0020}.
The intended solution was to get all the event entries of the pushhh event, as all secrets were broadcasted.
