Simple CTF Hints
Challenge 1 - FTP
If you have a fully working Internet connection, this challenge should be trivial. However, many networks provide only partial or intentionally restricted connectivity. This challenge aims to demonstrate how those
deficiencies or restrictions can prevent some things from working.
You should use a fully operational Internet connection for network pentesting, if your connection has deficiencies then you will be unable to thoroughly test targets. Scan results can also miss things due to your
own broken connectivity rather than configuration of the target systems, depending on the services and protocols being used by the target systems.
Challenge 2 - HTTP
For challenge 2, look at features of the HTTP protocol. Don't concern yourself with the page content, the flag will be obvious once you send the right combination of HTTP parameters.
Challenge 3 - HTTP again
This challenge is similar to challenge 1, with a sufficiently capable network connection simply visiting the URL is enough, however certain broken connections will be unable to access it.
Challenge 4 - HTTP yet again
Challenge 4 is a combination of challenges 2 and 3, you need a fully working internet connection as well as an understanding of how the HTTP protocol works.
Challenge 5 - Email
Challenge 5 is similar to challenge 2, but adapted to email. You need a modern fully functional email provider and then it will work trivially. Gmail would work, but is explicitly blocked because that would be
too easy. Office365 would work too but not with the default configuration. Other providers YMMV.
Challenge 6 - HTTPS
Challenge 6 is simply to access an HTTPS website which is set up to use some modern technologies. Safari on iOS or macOS should work flawlessly and access the site immediately, but other browsers support tends to be lagging behind.
Challenge 7 - Obfuscation
View the file using 'cat' or a random text editor, what do you see? Now view it with hexdump and see?
Challenge 8 - Protocols
There is more to the Internet than just TCP and UDP, in fact there are up to 256 possible protocols.
Challenge 9 - SSH
You cannot connect to the SSH service and retrieve the key that way, you must use a different way to retrieve the host key.