The Challenge

Google CTF seemed like a cool challenge so I attempted to solve it this year, having never attempted a CTF before.

The website for the CTF can be found here

My Solutions

The first problem had an attachment that when unzipped had two files, log.txt and rand2
log.txt contained random co-ordinates whilst rand2 contained a jumble of text when opened in vim
By doing a search in rand2 for CTF in vim, we find the first flag

On the second problem I was redirected to a YouTube video advertising the CTF competition here
At 0:17, moving frame-by-frame using , and . keys, we can see the next flag

The next problem was more tricky and required some more domain knowledge
The zip file contained 2 files this time, init_sat and README.pdf
README.pdf contained an image of a satellite with a useful name in it, Osmium
After looking around the contents of init_sat I realised it was an executable file in Linux, running it on Linux results in a terminal-like UI
Opening the Google Docs URL leads to a plain document with just some jumble of text
A common reversible encoding of text is Base64 - so after running the text through a decoder we get some hints
By re-running init_sat again with Wireshark open this time we can examine network activity and sniff for any calls made by the program on our network
After looking around we can find some calls that go to satellite.ctfcompetition.com, by doing Follow > TCP Stream we can see what the communications are in plain text
The flag is finally revealed here