Ok, back to it.
Level 11 (Save the U boat): Morse code. Do I need to say anything more? Grab the mp3 from the source code and do your best to translate the code. Maybe you can even find some software that does it for you.
Level 12 (I Still Know Where You been): Ever heard of EXIF data? Then get a nice map, preferably one that can show you images of around you, and have a look.
Level 13 (Secure Web Shell Client): I was quite lucky with this one. I was looking for a way to decrypt the text on the “shell” after base64 decoding, and found a wonderful function in python (I have used python for many of these challenges) that wonderfully decoded the text. Then it was only a matter of trying linux common commands to show part of the content of a file.
Level 15 (Easy Cryptography): Come on, you have to know the guy in the picture. If not, alea iacta est. Just research a bit about him and cryptography, and you’ll get it done. All to easy.
Level 16 (Polyalphabetic substitution): Did I ever mention a wonderful free cryptography tool called “cryptool”? It can solve this almost automatically. Go get it and learn how it works!
Level 17 (Apollo11 Moon hoax): Step one: translate those awkward symbols into something that a computer can handle better, like letters and numbers. Now, it is only a cryptographic substitution problem. Matching the letters & numbers you assigned to the alphabet may be a little bit tricky, but remember the solutions in this wargame usually start with “Password is : “. This is a good clue to start the decyphering with. Oh, by the way: for the end of the sentence, it is useful to be a gamer…
Level 18 (I want to play a game): Well, the technical par is not that hard: get the audio, grab an editing tool, and slow it down the best you can. Then listen to it and try to figure out about who are they talking about. Clue: his face is printed on tons of T-shirts and posters.
There is still more to come… somewhen I still haven’t found out level 19 – “Dead by April on tour!” (nobody has yet!), I have figured out a few things, but I need to make some hard work to see if things are like I figure. The problem? I too lazy for it. Maybe the next time I make a post about it and share the info I have found out so someone may give me a hand.
But I have solved some of the levels after 19, so if somebody needs a clue, just post a comment, and I’ll try to give you some not too obvious clues.