How to Install Chkrootkit on Debian 12/11/10

This article introduces you to an essential security tool, Chkrootkit, and how to install it on Debian-based systems such as Debian 12 Bookworm, Debian 11 Bullseye, and Debian 10 Buster. Chkrootkit is a valuable asset for system administrators and security professionals alike. It assists in detecting rootkits, which are a set of software tools usually employed by malicious actors to gain unauthorized access to a computer or network. By the end of this guide, you will have the know-how to install and utilize Chkrootkit on your Debian-based systems.

Let’s break down the key features and advantages of Chkrootkit:

  • Lightweight and Portable: Chkrootkit is known for its minimalistic approach, taking up very little disk space, and does not require extensive system resources.
  • Command Line Based: It operates through the command line, giving users full control and enabling them to script and automate tasks.
  • Versatile Detection Methods: Chkrootkit employs multiple techniques, including signature analysis and behavior monitoring, to identify and flag potential rootkits.
  • Open Source: As an open-source tool, Chkrootkit’s source code is available for public scrutiny, which typically results in more secure and reliable software due to community collaboration.
  • Cross-Platform Support: While this article focuses on Debian-based systems, Chkrootkit can also be used on a wide range of UNIX systems.
  • Regular Updates: Chkrootkit is actively maintained, ensuring that it is equipped to detect the latest rootkits and that known issues are resolved in a timely manner.

Having a security-focused tool like Chkrootkit installed and properly configured is an important step toward safeguarding your systems. With this guide, you will gain technical knowledge in installing Chkrootkit and develop an understanding of its functionality and importance in system security. This, in turn, equips you to take proactive measures in protecting your Debian systems, be it the latest Debian 12 Bookworm, the well-optimized Debian 11 Bullseye, or the reliable Debian 10 Buster, from rootkits and other malicious software.

Section 1: Setting Up Chkrootkit Using the APT Package Manager

Step 1: Refresh Package Lists and Upgrade

The first step in installing Chkrootkit is to refresh the package lists on your Debian Linux system. This is vital as it helps your system to have up-to-date information regarding the available packages and their versions. It also ensures that your system is primed with the latest security patches and software updates. To accomplish this, execute the following command in the terminal:

sudo apt update && sudo apt upgrade

This command retrieves the most recent package information from the repositories and upgrades any installed packages to the latest versions if available.

Step 2: Install Chkrootkit using APT

Now that your system is updated, the next step is to install Chkrootkit. The APT package manager, which is Debian’s default software management system, provides a streamlined approach to handle software installations. To use APT for installing Chkrootkit, execute the following command:

sudo apt install chkrootkit

Executing this command initiates the installation of the Chkrootkit package. This package comprises a collection of tools and scripts designed to detect and mitigate the presence of rootkits on your system. Rootkits are notorious for concealing unauthorized access to a system, and Chkrootkit helps in fortifying your system against such threats.

Step 3: Confirm Successful Installation

After installing Chkrootkit, it’s prudent to confirm that the installation was successful and that the software is properly set up and ready for use. Ensuring this will give you confidence in the integrity of the installation process and enable you to proceed with utilizing Chkrootkit effectively. To validate the installation, use the Chkrootkit version command by entering the following in the terminal:

chkrootkit -V

This command will display the version of Chkrootkit installed, affirming that the software is in place and operational.

Section 2: Installing Chkrootkit from Source Code

Step 1: Obtain the Chkrootkit Source Code

To start with, you need to download the source code of Chkrootkit from its official website. Doing so guarantees that you are obtaining the latest version of the software, which might include new features or security enhancements. In the terminal, navigate to the directory where you intend to store the source code. Then, execute the command below to download the Chkrootkit source code archive:


This command fetches the Chkrootkit source code in a compressed archive format, storing it in your specified directory.

Step 2: Unpack the Source Code Archive

After downloading the archive, the next action is to extract the source code. This step is indispensable as it enables you to access the files and directories necessary for the compilation and installation processes. To extract the source code, execute the following command:

tar -xvzf chkrootkit.tar.gz

Step 3: Compile and Set Up Chkrootkit

Prior to compiling Chkrootkit, it’s essential to ensure that your Debian Linux system has the requisite packages. These include the GNU Compiler Collection (GCC) and the make utility, which are indispensable for the compilation process. To install them, use the following command:

sudo apt install gcc make build-essential

Please note that the correct package name is build-essential and not build-essentials.

Now, navigate to the directory containing the extracted Chkrootkit source code. Use the cd command as shown below, but make sure to replace {your-version-number} with the actual version number of the downloaded Chkrootkit source code:

cd chkrootkit-{your-version-number}
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Executing this command compiles the Chkrootkit source code, generating an executable binary file.

Step 4: Confirm the Successful Installation

After compiling and setting up Chkrootkit, it is judicious to validate that the installation process completed successfully. This confirmation ensures that Chkrootkit is prepared and ready for utilization. To do this, execute the Chkrootkit version command as shown below:

./chkrootkit -V

This command displays the installed version of Chkrootkit, confirming that the software is correctly installed and operational.

Step 5: Move Chkrootkit to an Appropriate Directory and Make it Globally Accessible

After the successful compilation of Chkrootkit, it is advisable to move the Chkrootkit directory to a more standard location within the file system and make the executable accessible system-wide. A common practice is to place such software in /usr/local/bin for global accessibility.

Start by moving the Chkrootkit directory to /usr/local/share. First, ensure that you are in the parent directory of the Chkrootkit directory (one level above chkrootkit-{your-version-number}). Then, execute the following command:

sudo mv chkrootkit-{your-version-number} /usr/local/share/chkrootkit

Next, create a symbolic link to the Chkrootkit executable in /usr/local/bin. This makes Chkrootkit accessible from anywhere in the system without needing to navigate to its directory. Execute the following command to create the symbolic link:

sudo ln -s /usr/local/share/chkrootkit/chkrootkit /usr/local/bin/chkrootkit

Now, Chkrootkit is globally accessible. You can verify this by simply running the Chkrootkit version command from anywhere in the terminal:

chkrootkit -V

This additional step streamlines the utilization of Chkrootkit, making it easily accessible and aligning with standard practices for managing software installations on Linux systems.

Section 3: Leveraging Chkrootkit for Rootkit Detection

Preliminary Note: Running Chkrootkit with Elevated Privileges

Before diving into the steps, it’s crucial to note that when utilizing Chkrootkit for scanning your system, you will typically need to execute it with sudo. This is because Chkrootkit requires elevated privileges to thoroughly inspect all areas of your Debian Linux system, including those not accessible by unprivileged users. Running Chkrootkit with sudo ensures that it can effectively scan for rootkits across the entire system.

Now, let’s proceed to the steps for utilizing and scanning with Chkrootkit.

Step 1: Initiate Rootkit Scanning Using Chkrootkit

With Chkrootkit installed, it’s time to utilize its features to safeguard your Debian Linux system. A primary feature of Chkrootkit is to scan your system for any rootkits. Rootkits are malicious software that can give unauthorized access and control over your system. In a terminal, use this command to perform a thorough scan:

sudo chkrootkit

This command initiates a detailed scan, scrutinizing various elements of the system for irregularities that might indicate the presence of rootkits.

In case you desire a more streamlined output which only flags potential issues without overwhelming you with details, make use of the quiet mode:

sudo chkrootkit -q

This limits the output, making it easier to spot any red flags.

Step 2: Establish Automatic Scanning Regimen

Continuous vigilance is key in maintaining a secure environment. Chkrootkit can be configured to perform daily scans automatically. To achieve this, you need to tweak Chkrootkit’s configuration file.

Open the configuration file using this command:

sudo nano /etc/chkrootkit/chkrootkit.conf

In this file, search for the RUN_DAILY attribute and make sure its value is set to TRUE. This typically is the default setting, but confirming ensures that automated daily scans are active.


After editing, save the file by pressing CTRL + O and exit the editor by pressing CTRL + X.

If you installed Chkrootkit from source, as opposed to installing it from the Debian repositories, it does not come with a default configuration file like chkrootkit.conf. The chkrootkit.conf file is generally part of the packaged version of Chkrootkit that comes with Debian repositories.

When manually installing Chkrootkit from the source, you can run the tool directly without a configuration file. However, if you want to automate or configure the scans, you would need to create your own script or cron job to do so.

For example, if you want to create a daily cron job to run Chkrootkit, you could create a simple shell script to run the desired chkrootkit command, and then schedule this script using cron.

Here’s an example of how you can do it:

Create a script file, e.g.,


Make the script executable:

chmod +x

Edit the crontab file to schedule the script to run daily:

sudo crontab -e

Add the following line to the crontab file to run the script daily at a specific time (e.g., 2:00 AM):

0 2 * * * /path/to/

This way, you can effectively automate Chkrootkit scans even when installing from source.

Step 3: Delve into Chkrootkit’s Array of Commands and Documentation

For a tool as potent as Chkrootkit, understanding its capabilities is crucial. Chkrootkit comes with various commands and options that can be tailored to specific scanning needs.

Access the Help menu to get an overview of commands by executing:

chkrootkit -h

This provides a quick reference guide to Chkrootkit’s options and functionalities.

For an in-depth understanding, consider studying Chkrootkit’s manual page, accessible through:

man chkrootkit

This opens a wealth of information, with explanations of commands, options, and use cases for Chkrootkit.

Step 4: Experimenting with Advanced Scanning Options

Chkrootkit is equipped with specialized options to customize and enhance your scanning. For example, you can specifically check for a particular rootkit by specifying its name:

sudo chkrootkit wormscan

This command scans for worms.

Another advanced command lets you check for the last modification date of the network service binaries:

sudo chkrootkit -l /sbin

This example command inspects the /sbin directory for any modifications.

Using Chkrootkit effectively requires learning and experimenting with its various options to align the scans with your security objectives. Customizing the depth and focus of your scans allows for more robust and focused protection.

NOTE: Please exercise caution when using advanced commands. Incorrect usage may have unintended consequences.


In this article, we’ve navigated through the process of installing and configuring Chkrootkit on Debian Linux (versions 12/11/10). This involved obtaining Chkrootkit from the source, extracting and compiling the source code, and ensuring its proper installation. We also delved into the practical application of Chkrootkit for scanning and safeguarding your system against rootkits. By establishing an automated scanning regimen and familiarizing yourself with advanced scanning options, you empower yourself to maintain a secure computing environment.

In closing, it’s vital to keep abreast with updates and best practices in the security landscape. Utilizing Chkrootkit is an excellent step, but security is an ongoing process. Regularly check for software updates and continually educate yourself on security measures.

Additional Useful Links

To supplement your knowledge and expertise in using Chkrootkit on Debian Linux, here are some official resources and documents that you may find helpful:

  • Chkrootkit Official Website: The official Chkrootkit website is the hub for all things Chkrootkit. It’s the primary source for obtaining the latest version of Chkrootkit and accessing official documentation.
  • Chkrootkit FAQ: This link takes you to the Frequently Asked Questions (FAQ) page of Chkrootkit. It’s an excellent resource for getting quick answers to common questions and troubleshooting information.
  • Chkrootkit Book Recommendations: If you’re looking to deepen your knowledge about rootkits and security, this page on the official Chkrootkit website provides a list of recommended books.
  • Debian Official Security Information: This is the official security page of Debian Linux. It is an invaluable resource for staying informed on security advisories and best practices specific to Debian Linux.

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