How to block SSH brute force in Linux/Unix

I have a server who become crackers target to brute-force the SSH service. But, last time I checked, too many brute-force activities when I look into auth.log file.

So, I decide to block that's brute-force activities with this simple step:

1. Modify /etc/ssh/sshd_config
   This step is to ensure you will not receive SSH root account connected to your service.
   
   With root, open /etc/ssh/sshd_config file and find PermitRootLogin. Make sure your PermitRootLogin option is no, such as this:
   

   PermitRootLogin no

2. Add simple iptables entries
   The last step is add simple iptables entries to prevent brute-force activities.
   -A INPUT -p tcp -m tcp --dport 22 -m state --state NEW -m recent --set --name SSH --rsource -A INPUT -p tcp -m tcp --dport 22 -m recent --rcheck --seconds 30 --hitcount 4 --rttl --name SSH --rsource -j REJECT --reject-with tcp-reset -A INPUT -p tcp -m tcp --dport 22 -m recent --rcheck --seconds 30 --hitcount 3 --rttl --name SSH --rsource -j LOG --log-prefix "SSH brute force " -A INPUT -p tcp -m tcp --dport 22 -m recent --update --seconds 30 --hitcount 3 --rttl --name SSH --rsource -j REJECT --reject-with tcp-reset -A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
    (Taken from: rudd-o.com)

Snippets: How to find a value in memory using C++ (Windows)

At this moment, I just want to share some snippets about how to find some values stored in process memory on Windows environment.

This method check and avoid invalid memory region to be scanned, which make scanning process got an exception.

Snippets: Real-time display of `date` changes on Linux

In Linux environment, sometime you need how to know the time in realtime. With date command, you will see what the time is. But how to make it realtime?

With this simple command, you will see what is date command changes on your shell/console.

Finally!

Hi, I don't know how to make this blog updated for the future, I hope this silly blog give me more initiative to write more than I can imagine. LOL.

echo <<<EOF
HELLO WORLD!
EOF;