Archive for the 'FreeBSD' Category

Finding Ports to Install in FreeBSD

FreeBSD is founded on the idea that compiling is faster/better than using pre-made packages. To make compiling easy FreeBSD uses a “package management” system called ports; however, it is difficult to find the port to compile since FreeBSD’s package management system is really just empty directories with build instructions. These directories are categorized by the package application so that you can browse them, but it is difficult sometimes to find a package. Read more »

First Time Upgrading FreeBSD

If you remember from my post on my Initial Impression of FreeBSD 7.0 I am fairly new at using FreeBSD. After my recent Wordpress SQL Injection Attack I went around updating everything that I could get my hands on. A FreeBSD server happened to be one of those things that need updating. Read more »

Securely Wipe a File with DD

Sometimes we have sensitive data that we want to get rid of. Since deleting a file doesn’t actually prevent it from being recovered we need to do some extra steps to ensure that it can’t be recovered. In this post we will use DD to complete this task. DD is often the tool digital forensics use to duplicate hard drives we will use it for a more destructive use so that our data can’t be recovered. Read more »

Use Rsync for Daily, Weekly and Full Monthly Backups

Today, we will be using rsync to make daily, weekly, incremental backups and then a full compressed/archived backup once a month. We will then use cron to automate the process. Lets face it us humans get lazy sometimes and most backup systems loose complete effectiveness if they are not completely automated. Read more »

Duplicating a CD with DD

Want to make an exact copy of a CD without installing k3b or some other burning software? You can do it in Linux/Freebsd with one line of code using dd. The nice thing about dd is that it will make a disk level duplicate of the CD. It should be a 100% exact copy. Read more »

Make a Backup Image of your Hard Drive with DD

Dd is a tool that is often used in computer forensics because it is extremly low level and effecient at creating exact duplicates of hard drives. For this reason it is often the tool for which all other tools are compared to. But is it useful for us regular Joes?. Can we use dd to create digital copies of our hard drives for backup reasons? Yes we can, and I actually find that it is easier to use than commercially available solutions. Read more »

Protecting Linux from Fork Bombs

Fork bombs are basically a never ending loop. They open a processes that opens other processes that open even more processes exponentially. Causing any computer to lock up within a matter of seconds. Although they have to be ran from a logged in user they are still a threat. Users can unintentionally cause a complete lockup of a production server. Read more »

Add Port Knocking to SSH for Extra Security

SSH by default is very strong. It has protection against various hacks and known vulnerabilities. For instance SSH has a password retry wait time of five seconds. This makes the time for brute force attacking an SSH server very long and probably not effective. However, sometimes script kiddies will fork their hacking program making multiple processes of the brute force attack. Sometimes they are able to fork it off upwards of 1000 attempts every 5 seconds. This drastically minimizes the time to crack short passwords. Read more »

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