Security Archives - Sys Admin Guides, How To's, etc by Marios Maravelias

Get notified when root logs in.

Oct

29

2007

edit the file /root/.bashrc and add the following lines:

Checking if a server is under ddos attack

Jun

4

2007

A quick and usefull command for checking if a server is under ddos is: netstat -anp |grep ‘tcp\|udp’ | awk ‘{print $5}’ | cut -d: -f1 | sort | uniq -c | sort -n

Email Header Injection in PHP

Jun

4

2007

It has become apparent that spammers are getting even smarter than we take them for. Rather than abuse open relays, which are almost non-existent, these scum-of-the-earth ‘traders’ are now abusing contact forms.

SSH vs Script Kiddies How-to Guide

May

31

2007

Scope Some idiot created a SSH worm that uses a dictionary attack to try to log into a computer over port 22. The worm tries to set up shop on your computer and tries to find the next vulnerable computer. This clogs up networks with bazillions of SSH login attempts.

PHP Email Contact form with Captcha

May

30

2007

PHP Contact form with image verification.

What is a null route?

May

30

2007

What is a null route? A null route is a route that goes to nowhere. The reason for creating a null route is to prevent your system from sending any data to a remote system.