Here are some handy one liners that will allow you to check the number of connections to a port: #check port 25 netstat -an | grep “:25 “| grep ESTABLISHED | awk ‘{print $4″t”$5}’ | sort -n -k1 #check port 80 netstat -an | grep “:80 “| grep ESTABLISHED | awk ‘{print $4″t”$5}’ | sort …

It’s often required to block access to files in a folder by the file extension. For example – customer has an outdated version of oscommerce that they refuse to upgrade. It requires the images folder to have the permissions 777. The only thing that should be stored in the folder is images. To ensure a …

If you don’t have this setup already you should! This is a great method to ensure you’re notified each time the root user connects to your server via SSH. Edit the .bash_profile file of the user whose account you wish to monitor – typically: /root/.bash_profile echo ‘ALERT – Root Shell Access on:’ `hostname` `date` `who` …

We have seen a huge increase in individual servers/IP’s attempting to flood a server or brute force a particular account. Here’s a great way to check the number of connections being made from each IP that is connected to your server: netstat -an|awk ‘{print $5}’|cut -d “:” -f1|sort|uniq -c|sort -n We will post an automated …

This tip is especially important if you allow your clients SSH access. By default /home permissions are set to 755 which allows any user to cd /home and then list all of the user folders with ls -lah. This may not sound like too big of a security issue. However, if they’re a hacker or …