Reversing Warmup 1
Category : Forensics
Points: 50
Problem
Throughout your journey, you will have to run many programs. Can you navigate to /problems/reversing-warmup-1_3_7c0eade7faf60ffe3485e12098e2a6c2 on the shell server and run this program to retrieve the flag?
Hint
If you are searching online, it might be worth finding how to execute a program in the command line.
Solution
Referring to the hint, the problem is pretty easy to workaround. We just have to find a way to execute a program or file in the command line.
If you are downloading the file from the link just go to the directory where the file is present and run it by executing ./run where the run is the name of the downloaded file.
In case when you are executing in the shell in the website itself just go to the directory as given in the problem by running command cd /problems/reversing-warmup-1_3_7c0eade7faf60ffe3485e12098e2a6c2 to go the directory where our program is, as given in the question.
cdcommand stands for change directory and it’s used to go from one directory to another. You can read more about it here. When in the correct directory you can do ls to see all the files in that directory. lscommand is used to list contents of the current directory about which you can read here. The directory contains only one file called ‘run’. Just run that program by ./run like before. You will get a flag which should be entered in the text provided on the website and hit submit.
Solution Flag
picoCTF{welc0m3_t0_r3VeRs1nG}
Reversing Warmup 2
Category : Forensics
Points: 50
Problem
Can you decode the following string dGg0dF93NHNfczFtcEwzfrom base64 format to ASCII?
Hint
Submit your answer in our competition’s flag format. For example, if your answer was ‘hello’, you would submit ‘picoCTF{hello}’ as the flag.
Solution
We have another conversion here like in the general warmup. This time its base64 to ASCII conversion. Like the name suggests its a convertor with base 64. Each digit in it represents 6 bits of data. You can read more about base64 here.
Now coming to the conversion of base64 to ASCII (ASCII is nothing but a numerical representation of any number or letter or special character) you can go here. After decoding you will get a string like this th4t_w4s_s1mpL3. Enter that in the text provided and hit submit.
Solution Flag
picoCTF{th4t_w4s_s1mpL3}
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