Galera,
Sou iniciante no linux. Estava estudando sobre segurança no linux e li sobre os chamados rootkits. Instalei o rkhunter para testar o meu sistema e eis que apareceram tais mensagens:
[10:44:01] /usr/bin/unhide.rb [ Warning ]
[10:44:01] Warning: The command '/usr/bin/unhide.rb' has been replaced by a script: /usr/bin/unhide.rb: Ruby script, ASCII text
...
Info: Starting test name 'passwd_changes'
[10:44:53] Checking for passwd file changes [ Warning ]
[10:44:54] Warning: User 'postfix' has been added to the passwd file.
[10:44:54]
[10:44:54] Info: Starting test name 'group_changes'
[10:44:54] Checking for group file changes [ Warning ]
[10:44:54] Warning: Group 'postfix' has been added to the group file.
[10:44:54] Warning: Group 'postdrop' has been added to the group file.
...
[10:44:54] Info: Starting test name 'filesystem'
[10:44:54] Performing filesystem checks
[10:44:54] Info: SCAN_MODE_DEV set to 'THOROUGH'
[10:44:54] Checking /dev for suspicious file types [ Warning ]
[10:44:54] Warning: Suspicious file types found in /dev:
[10:44:54] /dev/.udev/rules.d/root.rules: ASCII text
[10:44:54] Checking for hidden files and directories [ Warning ]
[10:44:54] Warning: Hidden directory found: '/etc/.java'
[10:44:54] Warning: Hidden directory found: '/dev/.udev'
[10:44:54] Warning: Hidden file found: /dev/.initramfs: symbolic link to `/run/initramfs'
[10:45:07]
[10:45:07] Info: Test 'apps' disabled at users request.
...
[10:45:07] System checks summary
[10:45:07] =====================
[10:45:07]
[10:45:07] File properties checks...
[10:45:07] Files checked: 134
[10:45:07] Suspect files: 1
[10:45:07]
[10:45:07] Rootkit checks...
[10:45:07] Rootkits checked : 292
[10:45:07] Possible rootkits: 0
[10:45:07]
[10:45:07] Applications checks...
[10:45:07] All checks skipped
[10:45:07]
[10:45:07] The system checks took: 1 minute and 16 seconds
[10:45:07]
[10:45:07] Info: End date is Qui Nov 15 10:45:07 BRST 2012
Não coloquei o arquivo de log inteiro. Apenas as partes que informavam sobre os warnings. Preciso preocupar-me?