I was given [2 DLL files][1] . The task is to get the flag from them. First what I've done - opened the first file (called `original`) in IDA and found the function called `_GetFlag`. [![enter image description here][2]][2] As I understood, I need to call that function from the DLL library somehow (that's the first question - I don't have any info about the function except its name, so I'd like to know how exactly I can call it). However, as wee see, even if I knew how to call it, we can't get the flag from `original` DLL, it says `Sry, flag is in the patched version`. Ok, I opened `patched` DLL in IDA. First what we see that the file can be opened only as a binary: [![enter image description here][3]][3] As always, I opened the Strings window and we see the string `"0day is bring your own header day! Flag is: %s"` . It looks like a key for solution. [![enter image description here][4]][4] However, I don't exactly know what to do after that. I'd really appreciate if somebody would explain me how to solve this. [1]: https://mega.nz/#!w0RnhJTQ!_j3sImHX2Heo0Zb35rZw6uKYLFz8FTqoSmnE-zZDrVs [2]: https://i.sstatic.net/nur45.png [3]: https://i.sstatic.net/yCFF3.png [4]: https://i.sstatic.net/izwnv.png