# rkhunter > Searches for rootkits and malware. > More information: . - Check a system for rootkits and malware: `sudo rkhunter --check` - Update rkhunter: `sudo rkhunter --update` - Print all available tests: `sudo rkhunter --list` - Display version: `sudo rkhunter --versioncheck` - Display help: `sudo rkhunter --help`