EasyCTF IV 2018 Writeups

This is a collection of my writeups for challenges in EasyCTF IV

Details

EasyCTF IV
High School Hacking Competition
February 10 to February 20, 2018

Result

5206/6066 points (12th place)

Solved

Challenge	Category	Points	Remarks
Discord	Misc	1
Intro: Hello, world!	Intro	10
Intro: Linux	Intro	10
The Oldest Trick in the Book	Intro	10
Intro: Web	Intro	10
Soupreme Encoder	Cryptography	20
Intro: Netcat	Intro	20
Intro: Hashing	Miscellaneous	20
Programming: Exclusive	Programming	20
Haystack	Forensics	30
Look At Flag	Forensics	30
EzSteg	Forensics	30
Intro: Reverse Engineering	Intro	30
Programming: Taking Input	Programming	30
Programming: Over and Over	Programming	30
Programming: Teaching Old Tricks New Dogs	Programming	40
hexedit	Reverse Engineering	50
Substitute	Cryptography	50
Markov's Bees	Linux	50
xor	Cryptography	50
Programming: Subset Counting	Programming	55	@
Liar	Reverse Engineering	70
In Plain Sight	Web	70
Adder	Reverse Engineering	80
My Letter	Forensics	80
Nosource, Jr.	Web	80
Zippity	Miscellaneous	80
Flag Time	Miscellaneous	80
Starman 1	Programming	80	@
Keyed Xor	Cryptography	100
Not OTP	Cryptography	100	@
Diff	Forensics	100
rop1	Binary Exploitation	100
Remember Me	Forensics	130
EzReverse	Reverse Engineering	140
Soupstitution Cipher	Reverse Engineering	150
Digging for Soup	Web	150
MalDropper	Reverse Engineering	160
Zipperoni	Miscellaneous	160
format	Binary Exploitation	160
Starman 2	Programming	175	@
RSA_v	Cryptography	200
Souper Strong Primes	Cryptography	200	@
Pixelly	Reverse Engineering	220	@
Little Language	Miscellaneous	250	@
Nosource	Web	250
Hidden Key	Cryptography	250	@
fumblr	Web	275
Special Endings	Forensics	350	@
Fanfic Studio	Binary Exploitation	350

Unsolved

Challenge	Category	Points	Remarks
AES	Cryptography	160
The Walls Have Ears	Networking	325	Removed by organisers
LicenseCheck	Reverse Engineering	300
RSA Returns	Cryptography	400