HackTheBox Fast Carmichael Writeup
Explore the basics of cybersecurity in the Fast Carmichael Challenge on Hack The Box. This very-easy-level Challenge introduces encryption reversal and file handling concepts in a clear and accessible way, perfect for beginners.
https://app.hackthebox.com/challenges/416
Description
You are walking with your friends in search of sweets and discover a mansion in the distance. All your friends are too scared to approach the building, so you go on alone. As you walk down the street, you see expensive cars and math papers all over the yard. Finally, you reach the door. The doorbell says "Michael Fastcar". You recognize the name immediately because it was on the news the day before. Apparently, Fastcar is a famous math professor who wants to get everything done as quickly as possible. He has even developed his own method to quickly check if a number is a prime. The only way to get candy from him is to pass his challenge.
Exploitation
https://gist.github.com/keltecc/b5fbd533d2f203e810b43c26ff9d17cc
1
99597527340020670697596886062721977401836948352586238797499761849061796816245727295797460642211895009946326533856101876592304488359235447755504083536903673408562244316363452203072868521183142694959128745107323188995740668134018742165409361423628304730379121574707411453909999845745038957688998441109092021094925758212635651445626620045726265831347783805945477368631216031783484978212374792517000073275125176790602508815912876763504846656547041590967709195413101791490627310943998497788944526663960420235802025853374061708569334400472016398343229556656720912631463470998180176325607452843441554359644313713952036867
Send the following value as p to the server, and the flag will be displayed
Summary
The Fast Carmichael Challenge on Hack The Box introduces beginners to cybersecurity fundamentals by exploring encryption reversal and file handling. Participants solve a playful storyline centered around “Michael Fastcar,” a math professor famous for his quick methods of prime checking. By exploiting the provided clues and understanding the cryptographic weakness, participants can reverse-engineer the encryption to retrieve the flag. This very easy-level challenge is perfect for newcomers eager to practice basic cryptographic and problem-solving skills.