Happy new year and a small christmas gift!

November was a pretty busy month with exams and assignments to be delivered. I have been having a lot of fun with the MBA since analysing financial statements is some kind of reverse engineering and I missed Economics stuff (I have a undergraduate degree in Economics). I really like to go outside the box for some time to gain new perspectives. Since the 1st term is finished, I decided to finally upgrade to Snow Leopard....

December 26, 2009 · 2 min · 231 words · fG!

Snow Leopard impact into reverse engineering world...

Some folks were complaining about problems with otx and Snow Leopard so I decided to boot my Snow Leopard install and give it a try… Well they were right since Snow Leopard compiles 64 bit binaries by default. otx v0.16b seems to have problems so you will need to download from the SVN and compile yourself the most recent version. If you try to follow the tutorial you will have problems because you will have 64 bit registers (rax instead eax, for example) so you need to adapt the tutorial....

October 29, 2009 · 2 min · 225 words · fG!

Small gdbinit update...

Things have been very quiet since the beginning of September… Well my MBA has started and my free time until now has been ZERO! It has been a fun but very busy ride and comeback to the world of economics. The first weeks are recruit like, pretty intensive with many assignments to be delivered. The recruit is now over and I should have more free time for playing again with reversing 😄....

October 11, 2009 · 2 min · 226 words · fG!

GDB patches

Here you have the patches I did for GDB: To fix problem with gdbinit To display raw bytes in x/i and disassemble commands To warn about possible number of sections anti-debug trick You can download a single patch for all changes or one for each individual change. A patched GDB binary for Intel only is available, if you trust my binaries (copy to /usr/libexec/gdb). PHP max upload size doesn’t let me add the patched source package (can’t change it due to its impact on others)....

August 26, 2009 · 2 min · 249 words · fG!

Anatomy of a GDB anti-debug trick part II: GDB isn’t alone!

After having found the source of the GDB anti-debug trick, I started modifying GDB to work around the problem and fix the number of sections on the fly (it’s simple to calculate the real number of sections). I was coding on a long train trip and everything was going great… My hack worked and GDB fixed and loaded the file without a problem. Next step was to run the program but when I tried I had this surprise:...

August 26, 2009 · 4 min · 847 words · fG!