Linux Malware Detect (LMD) is a malware scanner for Linux released under the GNU GPLv2 license, that is designed around the threats faced in shared hosted environments. It uses threat data from network edge intrusion detection systems to extract malware that is actively being used in attacks and generates signatures for detection. In addition, threat data is also derived from user submissions with the LMD checkout feature and from malware community resources. The signatures that LMD uses are MD5 file hashes and HEX pattern matches, they are also easily exported to any number of detection tools such as ClamAV.
The driving force behind LMD is that there is currently limited availability of open source/restriction free tools for Linux systems that focus on malware detection and more important that get it right. Many of the AV products that perform malware detection on Linux have a very poor track record of detecting threats, especially those targeted at shared hosted environments.
The threat landscape in shared hosted environments is unique from that of the standard AV products detection suite in that they are detecting primarily OS level trojans, rootkits and traditional file-infecting viruses but missing the ever-increasing variety of malware on the user account level which serves as an attack platform.
Using the CYMRU malware hash registry, which provides malware detection data for 30 major AV packages, we can demonstrate this shortcoming in current threat detection. The following is an analysis of 8,882 MD5 hashes that ship in LMD 1.5 and the percentage of major AV products that currently detect the hashes.
MD5 file hash detection for quick threat identification
HEX based pattern matching for identifying threat variants
statistical analysis component for detection of obfuscated threats (e.g: base64)
integrated detection of ClamAV to use as scanner engine for improved performance
integrated signature update feature with -u|–update
integrated version update feature with -d|–update-ver
scan-recent option to scan only files that have been added/changed in X days
scan-all option for full path based scanning
checkout option to upload suspected malware to rfxn.com for review/hashing
full reporting system to view current and previous scan results
quarantine queue that stores threats in a safe fashion with no permissions
quarantine batching option to quarantine the results of a current or past scans
quarantine restore option to restore files to the original path, owner and perms
quarantine suspend account option to Cpanel suspend or shell revoke users
cleaner rules to attempt removal of malware injected strings
cleaner batching option to attempt cleaning of previous scan reports
cleaner rules to remove base64 and gzinflate(base64 injected malware
daily cron based scanning of all changes in the last 24h in user homedirs