Greetings former Mars settlers.

I'm pleased to see you are still alive, but know this will not last long. The remaining time you have left on Mars is minimal. In fact, there are less than three hours remaining before the attack I've started on NASA's network will be finished. You're probably wondering "Why should I care? Nothing like this is every serious and usually the hacker just gets bored," I understand your ignorant thoughts. But, just know this isn't a simple attack. Once the attack finishes, all systems on the Mars base will be stopped. This includes electrical, HVAC, operational, and wireless systems. Essentially, everything that keeps you alive will cease to exist. You will cease to exist.

Enjoy life while you can. There is very little time remaining now.
your death is immediate

Wait, I apologize. Maybe I've been a bit too harsh.
Instead, I'll give you a chance to make it out. There are some clues hidden on this page that may inform you of who I am. I've been a little reckless, I'll admit, and didn't clean up my trail as much as I usually do. If you can find the pieces of me left behind, you'll know where to look for next to figure out who I am. Let me tell you now, it won't be easy. But if you care about your life and the lives of the other astronauts here, you'll put in some effort.

Best wishes. Yours in the Stars,

We'll keep it simple for the first step. You're cybersecurity professionals hired by NASA, afterall. And you were formerly my colleagues. Clearly, you knew something like this was capable of happening and now LOOK AT YOU. YOU KNOW HOW TO FIND INVISIBLE TEXT. But, you know me. And I know you. One of the first things you were taught how to do was inspect the source code of a page. So, again, I'm taking it easy on you for now. Look at the source code and find the message I've hidden there for you. It'll let you know where to head next.