Linux Malware Detect (maldet)

Linux Malware Detect (maldet) is a widely-used open-source malware scanner designed for Unix-based systems, primarily focusing on detecting and identifying malicious software. It is particularly useful for administrators and security professionals looking to monitor and protect Linux servers from malware infections. Here's an overview of maldet and its key features:

Purpose of maldet

The main purpose of maldet is to:

• Detect and identify known malware, viruses, and malicious software on Linux systems.

• Provide administrators with tools to scan files, directories, and system areas for signs of compromise.

• Help in identifying and removing malware to maintain system integrity and security.

Features and Functionality

1. Malware Detection: maldet uses signature-based scanning techniques to identify known malware and viruses. It compares files against a database of known malicious signatures.

2. File and Directory Scanning: Administrators can specify files, directories, or system areas to scan for malware. This includes web server document roots, system binaries, and other critical directories.

3. Quarantine and Removal: Detected malware can be quarantined or removed based on administrator preferences. Quarantined files are moved to a safe location for further analysis.

4. Email Notifications: maldet can be configured to send email notifications when malware is detected, helping administrators stay informed about security incidents.

5. Integration with ClamAV: Optionally, maldet can integrate with ClamAV, another popular open-source antivirus software, to enhance malware detection capabilities.

Usage

Here’s a basic overview of how to use maldet:

1. Installation: Install maldet using your Linux distribution’s package manager or download it from the official website.

   sudo apt-get install maldet   # For Debian/Ubuntu

2. Update Malware Signatures: Before scanning, update maldet’s malware signature database to ensure it can detect the latest threats.

   sudo maldet --update

3. Scan Files/Directories: Perform a scan on specific files or directories. For example, to scan /var/www:

   sudo maldet -a /var/www

4. Review Scan Reports: After the scan completes, review the maldet scan report (/usr/local/maldetect/logs by default) to identify any detected malware.

Example Output

Upon running maldet, you might see output similar to the following in the scan report:

Linux Malware Detect v1.6.4
            (C) 2002-2017, R-fx Networks <[e-mail]>
            (C) 2017-2020, Ryan MacDonald <[e-mail]>
This program may be freely redistributed under the terms of the GNU GPL

maldet(30731): {scan} signatures loaded: 17829 (13807 MD5 | 4012 HEX)

Linux Malware Detect - Finding and Cleaning Malware:
/usr/local/apache/htdocs/images/malware.php: PHP.Globals - cleaned
/usr/local/apache/htdocs/files/backdoor.php: PHP.SpyWebshell - quarantined
/usr/local/apache/htdocs/files/infected.gif: Image.GIF.Exe - ignored

Security Considerations

• Regular Scanning: Perform regular maldet scans on critical systems to detect malware promptly.

• Updates: Keep maldet and its signature database up-to-date to ensure it can detect the latest threats effectively.

• False Positives: Like any malware scanner, maldet may occasionally report false positives. Verify findings before taking action.

Conclusion

maldet is a valuable tool for Linux administrators and security professionals seeking to protect their systems from malware infections. By integrating maldet into routine security practices, administrators can enhance the security posture of their Linux servers and respond proactively to potential security threats.