Shearwater CTF: Adults Only

The first challenge in the AusCERT 2016 Shearwater CTF I tried was a fairly simple one, it said that the programming language was adults only and that the flag was in a file they offered for download. The contents were:

++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>++++++++++++++++++++++++++++++.>++++.-----------.++++++.++++++++++++++++++++.---------------------------------------------------------.++++++++++++++++++++++++++++++++++++.<-------.>>+++++++++++++++++.++++++++++.-----.<<+.>>++++++.<<-.>------------------.<+++++++++.<++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.>---------.>>-.<-----------------.<++.>+++++++++++++++.<<+++++++++++++++++++++++++++++++++++++++++++++++++++++++++.++++.

It happens that due to my rather scattered experience I’d seen this rather hilarious language before, called brainfuck.

I found an online brainfuck interpreter and pasted it in, getting the flag.

flag{Bf_isn`t_Th@_sCaRy}



#AustCERT2016 #CTF #brainfuck