How-To

How to become a Linux security expert?

Demand for Linux security experts has risen over the last years. This article shows the relevant Linux security topics and required skills. Do you master them?

Summary of How to become a Linux security expert?

Years ago it was a challenge to find screenshots of devices running Linux. Nowadays, Linux can power phones, TV’s, computer systems, mainframes, and many more devices. With more devices, the demand for Linux knowledge will continue to grow. At the same time, the demand for security is higher than ever. All the media attention and regulations like GDPR, asks for more Linux security specialists. In this post, the goal is to answer the question: How to become a Linux security expert?

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How to secure a Linux system

Looking to secure your Linux system? This security guide shows you how to perform system hardening and run technical audits to keep it in optimal condition.

Summary of How to secure a Linux system

Every Linux system will benefit from more security, especially if it contains sensitive data. With so many resources available on the internet, one might think that securing Linux has become easy. We know it is not. Linux system hardening takes a good amount of understanding about how the Linux kernel works. It also requires a good understanding of the operating system principles. In this guide, we will help you to get this understanding and provide you with tips and tools.

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How to see the file type?

Learn how to determine the details of most types of files on Linux, together with the understanding how these tools do their job.

Summary of How to see the file type?

Did you come across a file, but don’t know what type it is? Let’s learn how to analyze it. The unknown file You may encounter a file on your system with known contents or goal. Usually, the first thing we do is then use cat to show the contents, or execute it. While that makes sense, it may be dangerous to do. It might be a piece of malware, disrupt your screen output or even hang the terminal.

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How to see the version of Oracle Linux

Oracle Linux is based on Red Hat Enterprise Linux. At first, it may be confusing to determine what specific Oracle version of the operating system is used.

Summary of How to see the version of Oracle Linux

Determine Oracle Linux version Oracle Linux is based on Red Hat Enterprise Linux. At first, it may be confusing to determine what specific operating system is running. This is because both have the /etc/redhat-release file. If that file exists, use the cat command to display the contents. Next step is to determine if there is a /etc/oracle-release file as well. If so, then you can be sure that Oracle Linux is running.

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How to solve an expired key (KEYEXPIRED) with apt

Software updates and package management is easy, until you get a KEYEXPIRED message. In this article we should how it happens and the way to solve it.

Summary of How to solve an expired key (KEYEXPIRED) with apt

Software updates and package management is easy with systems based on Debian or Ubuntu. Just apt-get update (or apt update) and run an upgrade. But sometimes you may encounter the following situation: a KEYEXPIRED message. KEYEXPIRED message # apt-get update && apt-get upgrade Get:1 http://security.ubuntu.com/ubuntu xenial-security InRelease [94.5 kB] Hit:2 http://nl.archive.ubuntu.com/ubuntu xenial InRelease Get:3 http://nl.archive.ubuntu.com/ubuntu xenial-updates InRelease [95.7 kB] Hit:4 http://nl.archive.ubuntu.com/ubuntu xenial-backports InRelease Hit:5 https://packages.cisofy.com/community/lynis/deb stable InRelease Get:6 http://nl.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages [373 kB] Ign:7 http://nginx.

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How to use grep (with examples)

Grep is a powerful utility on Linux. Want to get more out of the tool? This article will show you how to use it including many practical examples.

Summary of How to use grep (with examples)

The grep command is one of the oldest tools for Linux and other platforms. Actually, it is older than Linux itself. It was written by Ken Thompson more than 45 years ago! The name grep stands for “globally regular expression print”. This name comes from its predecessor ed and the specific mode in which you would globally search, using a regular expression, and print the output. The related command was “g/re/p”.

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