SSH or how to remotely control a UNIX system in a secure manner. The SSH keys is a secure method to interact with a UNIX system remotely. They are also used to transfer data between different systems. Using clever cryptography anyone can use them. As their name state it is a pair of keys, one […]
The LAMP stack (Debian 9)
LAMP stack stands for a software stack composed by Linux, Apache, MySQL and PHP (or Perl). It is used for many purposes and its common ground for system administrators. Since there are several of Linux distributions there are some differences in the way the LAMP stack is installed. In this guide we are using the […]
How to install Suricata on FreeBSD
Suricata is a free, open source, Intrusion Detection System software, or IDS for short. But it can also act as an Intrusion Prevention System, or IPS. It works by finding patterns using heuristics typically from network traffic. When configured to just warn about suspicious activity it is called an IDS, however when it blocks the […]
How to secure the ELK stack on CentOS 8
This is a follow up of the ‘how to install the ELK stack on CentOS 8’. That is a basic setup with no security at all. There is no encryption, no username and password setup, nothing. Not even firewall rules to filter ports. And as it’s known security can’t only rely on one factor but […]
A brief introduction to Regular Expressions
A regular expression is a set of characters, a string of characters if you will, that specify a pattern. Ever used the grep command? It makes use of them. The ‘grep’ command is very handful when one needs to look for certain things inside a text file, or looking for some specific pattern from another […]
Nmap cheatsheet
Nmap is a discovery tool used in security circles but very useful for network administrators or sysadmins. One can get information about operating systems, open ports, running apps with quite good accuracy. It can even be used in substitution to vulnerability scanners such as Nessus or OpenVAS for not very large environments, or quick audits. […]
How to patch Spectre and Meltdown the ROM way
In a previous article I briefly, sort of, talked about the Spectre and Meltdown vulnerabilities. I have also written two guides to patch them from the OS side using a UNIX flavour from the BSD camp and a GNU/Linux distribution. Both actions resulted successful but there is a third way to patch this vulnerabilities. Regular […]
Abandon Linux. Rolling back the entire OS is possible.
When I was writing an article on updating FreeBSD from the 11.2 version to the new major release number 12, I was trying to add something extra for those who may read some of the information I publish. FreeBSD as a UNIX operating system has similar functionality to the old school UNIX ones such as […]