Day 2

misc/red-phish-blue-phish

We are given the name of an employee, Sarah Williams, her mail, [email protected], and last but not least the company name: Pyrch Data. We also know that we had to do some OSINT to solve this one.

With a simple google search, we can find the company website at https://pyrchdata.com/. Which we will use to find other employee name and position.
For example Joe Daveren who is the IT Security Manager. We will assume that his mail is [email protected], following the one of Sarah.

We are given a port and a domain name to connect to, we know that it is a SMTP server using netcat: nc challenge.ctf.games XXXX
With that we can connect directly to the server to confirm that Joe mail is indeed [email protected] like so:

220 red-phish-blue-phish-10890ae31dadacde-55b9bcb4ff-5bpb7 Python SMTP 1.4.6
> EHLO all
250-red-phish-blue-phish-10890ae31dadacde-55b9bcb4ff-5bpb7
250-SIZE 33554432
250-8BITMIME
250-SMTPUTF8
250 HELP
> MAIL FROM: [email protected]
250 OK

To find the flag, we will use Swaks which will help us to send a mail from any mail to any other mail directly from this server.

Here the command will be something like that:

swaks --from [email protected] --to [email protected] --header 'Subject: Notification' --body 'Message' --server challenge.ctf.games:30828

The result of that command will contain the flag we need.

crypto/no-need-for-brutus

Category: Cryptography
Author: nalo_

We are given an encrypted string. A simple verification using CyberChef and we can find it’s a ROT10 (Cesar Code 10 rotations), given the clear message.

Wrapping it with flag{} and we got the final flag!