It is easy to use IDA pro to inspect program flow which create 10 thread and write something to file "key.txt". So it is easy to guess that content wrote in "key.txt" is the answer.
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| Flow of t100.exe |
2012年8月12日 星期日
HIT2012 Wargame Writeup : Binary 7
This is Binary 1 writeup in HITCON 2012. Binary1 is the easiest binary problem. This problem give an executable and make you read the key.
It is easy to use IDA pro to inspect program flow which create 10 thread and write something to file "key.txt". So it is easy to guess that content wrote in "key.txt" is the answer.
There are decompile code that each thread.
Those threads sleep some times of a random number then print some characters to file.But without give rand function a seed, all random number produced in each thread is the same.So we can easily sort the characters in each thread by there sleep and get the key.
It is easy to use IDA pro to inspect program flow which create 10 thread and write something to file "key.txt". So it is easy to guess that content wrote in "key.txt" is the answer.
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