This is a write up to the 2014 CactusCon web application (SpookiLeaks) challenge. You can grab the SpookiLeaks-VM here and try the challenge yourself before reading the solution.
I maintain several Linux servers at any given moment. Every server has postfix installed for sending emails, usually notifications or warning messages of some sort and most of these servers are professionally hosted allowing outbound emails with little to no configuration beyond installing postfix. However, my home server lies behind my ISP and they block all outbound emails citing SPAM as the reason. Regardless of their reasoning I had to find a workaround to allow me to send email notifications from behind my ISP. Well, it turns out this is rather painless with postfix and a Gmail account.
Having set up several Debian and Ubuntu web servers in the past I thought it would be a good idea to share my process. The following is a relatively comprehensive guide to installing and configuring an Apache based web server with some optimizations and basic resource monitoring. I primarily work with Ubuntu servers, but most of the commands here should work exactly the same in Debian or Ubuntu. I've tried to note where differences may occur.
I work in Linux primarily but run a Windows 7 virtual machine in VirtualBox so I can use Photoshop and do some necessary testing. Today my VM ran out of space. Silly me thought 20GB would be enough, but after installing service pack 1, dozens of Windows updates and a few programs I had less than 1GB of space left. After a little searching I found an easy way to increase the size of a virtual disk.
I was just in a bit of a pickle and needed to join two .avi files together while in Ubuntu. There are a number of solutions out there, but the most simple solution I could find was via avimerge. Here's how I did it.