hackers hour CTF: write-up

Raj Upadhyay

5 min readSep 29, 2020

Recently I participated in HackersHour CTF.

My team was able to secure the 5th rank in CTF.

I was able to solve all the “Mics Challenges” so here is how I solved them.(https://ctf.hackershour.org/)

Mics Challenges

1.FlauntingFonts

So let’s try to open the zip file. we got one PDF file.

But it asks for a password. so I cracked it online.

PDF file looks like this,

So I scrolled some pages. I came across some wired text it looks like this

So the flag was in front of me. I just need to reverse it.

Flag : THM{fonts_aren’t_a_lie}

2. Loop

So we got one zip file.

After extracting the ZIP file we got this,

10 folders and each contains 10 files in it. So I know there will be a flag in some file. I manually opened all the files and got the flag.

Folder 8: File 4.txt

THM{yOu_soLVeD_tHE_LooP}

3.CallMeX

So we got one zip file.

we got one CallMeX.exe file which was wired.

So I thought let me see it in HEX editor.

And Boom we can see it’s a PNG file.

So changed the extension to .png

we got our flag

Flag : THM{ExTenSIons_CAN_fooL_You}

4.Baffled

So let’s open the ZIP file.

we got two files one is a PDF file and one if the ZIP file.

So let’s see the PDF file first.

we got one Pastebin link (pastebin.com/8S9V29QC)

So that page looks like this,

It was wired text but I come across this before so I know it’s kind of BrainFuck language.

I used “https://www.splitbrain.org/_static/ook/” this site to decode it.

Got some password, so now I know the password of the zip file. so let’s open it

And that folder contains our flag.

Flag : THM{miSceLLanEous_IncLudeS_maNY_tHingS}

5.BadGlitches

So let’s download the zip file and open it.

Interestingly we got one GIF file. I can see some text was present in the GIF file so,

I tried to do gif to text online converter.

Here we don’t need to do GIF to text conversion we can just decompile GIF into images and we can also find this flag.

Flag: THM{one_flag_many_effects}

6.Locked

Personally, I do not like this challenge (especially you need to download some specific tools to solve the challenge I hate that part.) Two of my Teammates (Tejas Pandya, Dharmik Fichadiya) solved this challenge.

So firstly as the name suggests we need to unlock the zip file to get content.

So with help of Fcrack we able to unlock the zip file. Password (pandemic)

So now we got one BMP image. To complete this challenge we need to use some tool that was given in HINT.

So I downloaded it and installed that tool. So with the use of that tool, we were able to get one zip file from that BMP image.

So when I opened “a” folder I see one jpg file so I opened it but I got an error so tried to open it with HEX editor.

So we got some Base64 data. so now let’s decode it. ( you are wondering how I know that it’s Base64 right? because I have played N-number of CTF so now I know how Base64 look like)

we got one paragraph and the flag was also there.

(GUZ{cNaqrZvp_jVyy_rAQ_f00A})

So I know it’s caesar cipher and I decoded it online.

Flag : THM{pAndeMic_wIll_eND_s00N}( i hope this line will soon become reality)

7.Brainstorm

So let’s download the zip file and extract it.

So usual we got one pdf file and one zip file.

So let’s open the PDF file first.

It’s morse code so let’s decode it.

Ohhhhhh it looks like we got a password but wait it will not work because all letters are the capital letters. So let’s first change it in small letters and try to open the zip file.

Yasss ‘ihaveyourflag’ worked.

So again we got one text file so let’s see what it contains.