5 Tools to Scan a Linux Server for Malware and Rootkits

As a Linux server owner, it's important to ensure your system is secure from malware and rootkits that can harm your data or steal sensitive information. Luckily, there are several tools available to help you scan your Linux server and detect any threats lurking in your system. In this article, we'll discuss five tools you can use to scan your Linux server for malware and rootkits.

ClamAV

ClamAV is an open-source antivirus software that can be used to scan Linux servers for malware. It's a lightweight and easy-to-use tool that can detect viruses, Trojans, and other malicious software. ClamAV supports various file formats, including compressed files and email attachments. It also supports integration of email servers, which allows you to scan incoming and outgoing emails for malware.

To use ClamAV, you need to install it on your Linux server. installation process varies depending on Linux distribution you're using. Once installed, you can use clamscan command to scan specific directories or files. For example, to scan /var directory, you can run following command −

clamscan -r /var

The -r option tells ClamAV to scan directory recursively. You can also use clamdscan command to scan files on-demand. For example, to scan a file called example.tar.gz, you can run following command −

clamdscan example.tar.gz

If ClamAV detects any malware or rootkits, it will quarantine or remove infected files, depending on your configuration.

Rkhunter

Rkhunter (Rootkit Hunter) is a command-line tool that can scan Linux servers for rootkits, backdoors, and other malicious software. It uses various techniques to detect suspicious files and processes, such as comparing checksums of system binaries and scanning for hidden files and directories.

To use Rkhunter, you need to install it on your Linux server. installation process varies depending on Linux distribution you're using. Once installed, you can run rkhunter command to scan your system. For example, to perform a full system scan, you can run following command −

rkhunter --checkall

Rkhunter will then scan your system and generate a report with any suspicious files and processes it detects. You should review report and take action on any findings.

Chkrootkit

Chkrootkit is a command-line tool that can scan Linux servers for rootkits and other malicious software. It uses various techniques to detect suspicious files and processes, such as scanning for known rootkit signatures and checking integrity of system binaries.

To use Chkrootkit, you need to install it on your Linux server. installation process varies depending on Linux distribution you're using. Once installed, you can run chkrootkit command to scan your system. For example, to perform a full system scan, you can run following command −

chkrootkit -q

Chkrootkit will then scan your system and generate a report with any suspicious files and processes it detects. You should review report and take action on any findings.

Lynis

Lynis is a command-line tool that can perform security audits on Linux servers. It scans your system for vulnerabilities and provides recommendations on how to improve your system's security. Lynis can also detect malware and rootkits by scanning for suspicious files and processes.

To use Lynis, you need to install it on your Linux server. installation process varies depending on Linux distribution you're using. Once installed, you can run lynis command to perform a security audit. For example, to perform a full system audit, you can run the following command −

Lynis Audit System

Lynis will then scan your system and generate a report with any vulnerabilities and recommendations it detects. It will also flag any suspicious files and processes it finds, which could be malware or rootkits.

OSSEC

OSSEC is an open-source host-based intrusion detection system (HIDS) that can be used to detect and respond to security incidents on Linux servers. It uses various techniques to monitor your system, including file integrity checking, log analysis, and rootkit detection.

To use OSSEC, you need to install it on your Linux server and set up an agent to monitor your system. installation process varies depending on Linux distribution you're using. Once installed, you can configure OSSEC to monitor your system and send alerts if it detects any suspicious activity, such as presence of a rootkit.

Tripwire

Tripwire is a file integrity checking tool that can be used to detect changes to your system files. It can help you detect unauthorized modifications to your system files, which could be an indication of a malware or rootkit infection. To use Tripwire, you need to install it on your Linux server and configure it to monitor your system files.

AIDE

AIDE (Advanced Intrusion Detection Environment) is another file integrity checking tool that can be used to detect changes to your system files. Like Tripwire, it can help you detect unauthorized modifications to your system files, which could be an indication of a malware or rootkit infection. To use AIDE, you need to install it on your Linux server and configure it to monitor your system files.

RKDetector

RKDetector is a rootkit detection tool that can be used to detect rootkits on your Linux server. It uses various techniques to detect rootkits, such as scanning for hidden processes and files. To use RKDetector, you need to install it on your Linux server and run rkdetect command.

LMD

LMD (Linux Malware Detect) is a malware scanner that can be used to detect malware on your Linux server. It uses various techniques to detect malware, such as signature scanning and heuristic analysis. To use LMD, you need to install it on your Linux server and run maldet command.

Conclusion

Scanning your Linux server for malware and rootkits is an important part of maintaining a secure system. By using tools discussed in this article, you can detect and respond to any threats that may be lurking in your system. Remember to keep your system up-to-date with latest security patches and follow best practices for securing your Linux server.