This write-up serves as a personal reference and a tool for me to practice FlareOn. It includes information and solutions collected from various sources.
Challenge
Challenge 1.zip : Challenge 1.zip
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# file Flare-On_start_2015.exe
Flare-On_start_2015.exe: PE32+ executable (GUI) x86-64, for MS Windows
Password: flare
Walkthrough & Solution
When you open the Flare-On_start_2015.exe , a license agreement will appear that you will need to accept in order to proceed.
After accepting the license agreement, the program will prompt you to choose a destination path where you want to extract the contents.
After extracting the contents, you will find a file named i_am_happy_you_are_to_playing_the_flareon_challenge.exe
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# file i_am_happy_you_are_to_playing_the_flareon_challenge.exe
i_am_happy_you_are_to_playing_the_flareon_challenge.exe: PE32 executable (console) Intel 80386, for MS Windows
When we run the program, it prompts us to enter a password. However, if we enter the incorrect password, the program outputs the message ‘You are failure’.
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PS > .\i_am_happy_you_are_to_playing_the_flareon_challenge.exe
Let's start out easy
Enter the password>flareon
You are failure
I’m going to open it with Ghidra. If you encounter an issue with a missing OpenJDK 17 installation on your Windows system, you can download it from this website: https://learn.microsoft.com/en-us/java/openjdk/download
Based on the decompiled entry function provided, the XOR operation performed in the code snippet will iterate over each byte of the user’s input, XOR it with the hexadecimal value 0x7d, and compare the result with the corresponding byte in another variable.
Let’s extract all the information we need and use python to get our flag.
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stored = b'\x1f\x08\x13\x13\x04\x22\x0e\x11\x4d\x0d\x18\x3d\x1b\x11\x1c\x0f\x18\x50\x12\x13\x53\x1e\x12\x10'
flag = ""
for i in stored:
flag+=chr(i^0x7d)
print(flag)
Flag : bunny_sl0pe@flare-on.com
References
- https://secwriteups.blogspot.com/2016/08/flare-2015-challenge-1.html
- https://www.ghettoforensics.com/2015/09/solving-2015-flare-on-challenges.html
- https://www.aldeid.com/wiki/The-FLARE-On-Challenge-2015/Challenge-1
- https://github.com/fareedfauzi/Flare-On-Challenges/blob/master/Write-ups/2015/2015solution1.pdf
- https://m.alvar.es/2015/10/fireeye-flareon-2015-challenges-1-3.html
- http://nieluj.github.io/flareon2/
- http://camelinc.info/blog/2015/08/FLARE-on-Challenge-2015/
- https://www.tophertimzen.com/blog/flareOn/
- https://blog.wirhabenstil.de/2015/09/09/fireeye-flare-challenge-2015-write-up-level-1/
- https://blog.csdn.net/weixin_53349587/article/details/122300468