Same as https://sourceforge.net/p/rkhunter/bugs/105/
~ $ rkhunter --update
[ Rootkit Hunter version 1.3.8 ]
Checking rkhunter data files...
Checking file mirrors.dat [ No update ]
Checking file programs_bad.dat [ No update ]
Checking file backdoorports.dat [ No update ]
Checking file suspscan.dat [ No update ]
Checking file i18n versions [ Update failed ]
Please check the log file (/var/log/rkhunter.log)
In /var/log/rkhunter.log:
[04:14:18] Info: Executing download command '/usr/bin/wget -q -O /var/lib/rkhunter/tmp/rkhunter.upd.7P8fZoA4xi http://rkhunter.sourceforge.net/1.3/i18n/1.3.8/i18n.ver 2>/dev/null'
[04:14:19] Checking file i18n versions [ Update failed ]
[04:14:19] Warning: Download of 'i18n.ver' failed: Unable to determine the latest version number.
Rootkit Hunter version 1.4.2 has been released a while ago now. Each new version deprecates the older version. You are using ancient version 1.3.8. Please update.