H@cktivityCon 2021

Tsunami

For this one we get an audio file, I opened the file in audacity and viewed the audio in the Spectogram view:

Bass64

The file leads to this:

Only when you zoom out, you then see actual string:

I then entered this on the website (base64decode.org) and ended up finding out the following:

Pimple

For this challenge, we get a file format meant for GIMP. Running file Pimple gives us the following: pimple: GIMP XCF image data, version 011, 1024 x 1024, RGB Color. I then opened the file in gimp, and after just browsing around, I found this:

Six Four Over Two

For this problem, we are given a file with the following information:

My mentality was that 64/2 or "six four over two" is 32. I ran the command echo "EBTGYYLHPNQTINLEGRSTOMDCMZRTIMBXGY2DKMJYGVSGIOJRGE2GMOLDGBSWM7IK" | base32 -d and this led me to the flag: flag{a45d4e70bfc407645185dd9114f9c0ef}

Confidentiality

For this challenge, we are sent to a webpage:

It seems that you can view any file and see it it exists:

My assumption was that in the backend ls was running. So I had to find a way to use one command to get the flag. I first tried just a ; and this is what it showed me:

All I had to do now, was to print the contents of the file. I ran ; cat flag.txt and got the flag:

2EZ

For this question we get a file with a incorrect header:

I changed the header to be ff d8 ff e0. I also changed the file from 2ez to 2ez.jfif. I then got the flag: