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[crackme] Little challenge ...

Go to solution Solved by mrexodia,

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yes ... the main purpose of this type of challlenge is examine the file and then, find its secret! A good start point is an Hex editor and, obviously, internet search! :-)

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  • Solution




  • Open up 'Cr4ckM3' in your favorite hex editor
  • First check if you can find the signature (first 4-8 bytes) on google: 3F 3F 3F 3F or 31 35 34 31 have no interesting results, let's look further down.
  • If you scroll down to 0x2D0 you will find a commonly-occurring pattern: A5 29 4A 52 94 <- various intersting hits on google!
  • First link: http://ist.uwaterloo.ca/~schepers/formats/G64.TXT tells us the file should start with 47 43 52 2D instead of 3F 3F 3F 3F. Change this and save the file with the extension .g64
  • Download WinVICE (commodore 64 emulator): http://www.zimmers.net/anonftp/pub/cbm/crossplatform/emulators/VICE/WinVICE-2.3-x86.zip
  • Open 'x64mm.exe' and use 'File->Autostart Disk image' and select our saved .g64
  • Appears to be running:


  • Download http://style64.org/dirmaster to browse the contents of the .g64 file
  • Let's look inside "SECRET":



  • Try "PEEKPOKE" as code and everything appears to be in order:


Mr. eXoDia

Edited by Mr. eXoDia
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The [crackme] tag has been added to your topic title.

Please remember to follow and adhere to the topic title format - thankyou!

[This is an automated reply]

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Well done Mr. eXoDia!  :thumbs: Your solution is certainly faster than mine ... probably an old C*4 user would have had a different approach  :smilie3:

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