CDDC 2019 Qualifiers Writeups

This is a collection of my writeups for challenges in CDDC 2019 Qualifiers

Details

Playtime
- Qualifiers: 31 May 2019 (Fri) 10:00 to 2 June 2019 (Sun) 10:00 (48 hours)
- Servers will stay open until 2 June 2019 23:59 for players to prepare documentation for challenge write-ups.

Score

My team (B55) scored 3rd place in the Poly/Uni category

Solved

Challenge	Category	Remarks
[R-0] Everyone <3 Fan Mail	OSINT_RED	x
[R-1] Travel to the Past	OSINT_RED	no writeup
[R-2] I'm Sho Done With This	OSINT_RED	no writeup
[R-3-1] Have They Been Pwned?	OSINT_RED
[R-3-2] cHash Me Outside How 'Bout Dat	OSINT_RED
[R-4-1-1] Who Uses Teams Anyway?	OSINT_RED	no writeup
[R-4-1-2] Don't Be A Git	OSINT_RED
[B-0] What's in, Doc?	OSINT_BLUE
[B-1] Fight the Binary Monster	OSINT_BLUE
[B-2] I <3000 PHISH	OSINT_BLUE
[B-3-1] Onion Sauce	OSINT_BLUE
[B-3-2] When Your ZIL Turns to NIL :'(	OSINT_BLUE
[B-4-1] Where I Get All My GIFs From	OSINT_BLUE	no writeup
[B-4-2] Hide N Seek	OSINT_BLUE	no writeup
[B-4-3] Caught by Summon Auntie	OSINT_BLUE	x
Not FairPrice, but FairPlay	Crypto
FunShop	Crypto
The Terrible Photographer Strikes	Forensics	x
UnZip	Forensics
Slackers, Unite!	Misc
Polyglot	Misc
Very Serious Challenge	Misc
Do You Fancy Numbers?	Misc	x
Super Strong TeleVision	Misc	x
Dot	Misc	x
TxT	Network
Count 1: Baby	Programming
Count 2: Wildness	Programming
Count 4: Madness - Filter	Programming
Lemonade	RE
LSCVM: Immaculate Invasion	RE
\'_'/	Web
EncryptSvc	Pwn

Unsolved

Challenge	Category	Remarks
Do Not Accept Your Fate	Misc
What Time Is It?	Misc
Travel The World	Misc
Count 3: Madness - Noise	Programming
LSCVM: Quintessential Harlequin	Programming
Come Back To Earth	RE
PPAP	Web

Other writeups

Other people's writeups for my own reference:

• https://blog.justins.in/cddc19q/
• https://d.oulove.me/2019/06/05/CDDC19-qual-writeup/
• https://dzhy.dev/2019/06/04/CDDC-2019-Qualifiers-Writeup/
• https://dzhy.dev/2019/06/14/CDDC-2019-LSCVM-Writeup/