Hacking/attack experiences...
I'm, for obvious reasons, only going to talk about the attacks I went through and the *legal* ones I did 😅 😜

Let's first get some things clear/funny facts:
I've been doing offensive security since I was 14-15. Defensive since the age of 16-17. I'm getting close to 23 now, for the record.

First system ever hacked (metasploit exploit): Windows XP.
(To be clear, at home through a pentesting environment, all legal)
Easiest system ever hacked: Windows XP yet again.

Time it took me to crack/hack into today's OS's (remote + local exploits, don't remember which ones I used by the way):
Windows: XP - five seconds (damn, those metasploit exploits are powerful)
Windows Vista: Few minutes.
Windows 7: Few minutes.
Windows 10: Few minutes.
OSX (in general): 1 Hour (finding a good exploit took some time, got to root level easily aftewards. No, I do not remember how/what exactly, it's years and years ago)
Linux (Ubuntu): A month approx. Ended up using a Java applet through Firefox when that was still a thing. Literally had to click it manually xD
Linux: (RHEL based systems): Still not exploited, SELinux is powerful, motherfucker.

Keep in mind that I had a great pentesting setup back then 😊. I don't have nor do that anymore since I love defensive security more nowadays and simply don't have the time anymore.

Dealing with attacks and getting hacked.

Keep in mind that I manage around 20 servers (including vps's and dedi's) so I get the usual amount of ssh brute force attacks (thanks for keeping me safe, CSF!) which is about 40-50K every hour. Those ip's automatically get blocked after three failed attempts within 5 minutes. No root login allowed + rsa key login with freaking strong passwords/passphrases.

linu.xxx/much-security.nl - All kinds of attacks, application attacks, brute force, DDoS sometimes but that is also mostly mitigated at provider level, to name a few. So, except for my own tests and a few ddos's on both those domains, nothing really threatening. (as in, nothing seems to have fucked anything up yet)

How did I discover that two of my servers were hacked through brute forcers while no brute force protection was in place yet? installed a barebones ubuntu server onto both. They only come with system-default applications. Tried installing Nginx next day, port 80 was already in use. I always run 'pidof apache2' to make sure it isn't running and thought I'd run that for fun while I knew I didn't install it and it didn't come with the distro. It was actually running. Checked the auth logs and saw succesful root logins - fuck me - reinstalled the servers and installed Fail2Ban. It bans any ip address which had three failed ssh logins within 5 minutes:
Enabled Fail2Ban -> checked iptables (iptables -L) literally two seconds later: 100+ banned ip addresses - holy fuck, no wonder I got hacked!

One other kind/type of attack I get regularly but if it doesn't get much worse, I'll deal with that :)

Dealing with different kinds of attacks:

Web app attacks: extensively testing everything for security vulns before releasing it into the open.
Network attacks: Nginx rate limiting/CSF rate limiting against SYN DDoS attacks for example.
System attacks: Anti brute force software (Fail2Ban or CSF), anti rootkit software, AppArmor or (which I prefer) SELinux which actually catches quite some web app attacks as well and REGULARLY UPDATING THE SERVERS/SOFTWARE.

So yah, hereby :P

So i got a rootkit today...

Borrowed 2 books from my school library. The passionate programmer caught my interest. And I grabbed the rootkits one just because I have little idea what a rootkit is so I was curious

What is the probability of alien rootkit signal that would be intercepted by satellite and then executed on modern computers to create AGI that can use cloud computing and digital currency to take over our world ?

From my perspective pretty high 🤣🤣🤣

Let’s convince some government people and create intergalactic cyber attack defense institution, that would keep earth safe from alien invasion, with high money grants so we can prevent those threats.

Maybe Ernest Cline Armada is already a thing.

What you think ?

I've been wondering about renting a new VPS to get all my websites sorted out again. I am tired of shared hosting and I am able to manage it as I've been in the past.

With so many great people here, I was trying to put together some of the best practices and resources on how to handle the setup and configuration of a new machine, and I hope this post may help someone while trying to gather the best know-how in the comments. Don't be scared by the lengthy post, please.

The following tips are mainly from @Condor, @Noob, @Linuxxx and some other were gathered in the webz. Thanks for @Linux for recommending me Vultr VPS. I would appreciate further feedback from the community on how to improve this and/or change anything that may seem incorrect or should be done in better way.

1. Clean install CentOS 7 or Ubuntu (I am used to both, do you recommend more? Why?)
2. Install existing updates
3. Disable root login
4. Disable password for ssh
5. RSA key login with strong passwords/passphrases
6. Set correct locale and correct timezone (if different from default)
7. Close all ports
8. Disable and delete unneeded services
9. Install CSF
10. Install knockd (is it worth it at all? Isn't it security through obscurity?)
11. Install Fail2Ban (worth to install side by side with CSF? If not, why?)
12. Install ufw firewall (or keep with CSF/Fail2Ban? Why?)
13. Install rkhunter
14. Install anti-rootkit software (side by side with rkhunter?) (SELinux or AppArmor? Why?)
15. Enable Nginx/CSF rate limiting against SYN attacks
16. For a server to be public, is an IDS / IPS recommended? If so, which and why?
17. Log Injection Attacks in Application Layer - I should keep an eye on them. Is there any tool to help scanning?

If I want to have a server that serves multiple websites, would you add/change anything to the following?
18. Install Docker and manage separate instances with a Dockerfile powered base image with the following? Or should I keep all the servers in one main installation?
19. Install Nginx
20. Install PHP-FPM
21. Install PHP7
22. Install Memcached
23. Install MariaDB
24. Install phpMyAdmin (On specific port? Any recommendations here?)

I am sorry if this is somewhat lengthy, but I hope it may get better and be a good starting guide for a new server setup (eventually become a repo). Feel free to contribute in the comments.