So first I would SSH into my box and grep through the logs for failed login attempts.
grep -i failed /var/log/auth.log | less
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First I took just one IP from my logs, and Nmap'd it (well they started it!). I found a single SSH port open running a vulnerable version of OpenSSH.
nmap -F 199.33.132.127 -PN
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Okay, so using nmap fast scan (looking for the most common ports) I see that port 22 is open.
Now I used a really great website called clez.net to look at the port in more detail.
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This site gives me the SSH version and plenty of other intresting info.
So now if I google the SSH version I quickly find that it's an old vulnerable version (OpenSSH 3.9p1).
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So it would seem that some poor sucker has got his box owned and now he is scanning my box.
So that's it really. I just wanted to demonstrate to anyone who might read this why it is important to patch.