The rkhunter tool is a security tool that scans your system for rootkits, backdoors, and possible local exploits. It checks for various signs of compromise, such as modified files, hidden processes, suspicious network connections, and more. To use the rkhunter tool, you need to install it on your system first. You can do this by running the following command in a terminal:

`sudo apt install rkhunter`

After installing the rkhunter tool, you need to update its database of known rootkits and malware. You can do this by running the following command:

`sudo rkhunter –update`

To scan your system for rootkits and malware, you can run the following command:

`sudo rkhunter –check`

This will perform various tests on your system and report any warnings or errors. You can also specify which tests to enable or disable, or which files or directories to scan, by using different options. For more information on how to use the rkhunter tool, you can read its documentation¹ or its manual page².

Another equivalent tool to find out rootkits in your system is chkrootkit. It is a shell script that checks for the presence of known rootkits, worms, and other malicious programs. You can install it by running the following command:

`sudo apt install chkrootkit`

To scan your system with chkrootkit, you can run the following command:

`sudo chkrootkit`

This will check for various signs of infection, such as hidden files, processes, ports, modules, and more. You can also specify which tests to run, or which files or directories to scan, by using different options. For more information on how to use chkrootkit, you can read its documentation³ or its manual page.