Persistence libraries/Mixins

lib/msf/core/exploit/local/persistence.rb

@@ -0,0 +1,74 @@
+# -*- coding: binary -*-
+
+module Msf
+  module Exploit::Local::Persistence
+    def initialize(info = {})
+      @persistence_service = Rex::Sync::Event.new(auto_reset=false)
+      @clean_up_rc = nil
+      super(
+        update_info(
+          info,
+          'DefaultOptions' => {},
+          # https://github.com/rapid7/metasploit-framework/pull/19676#discussion_r1907594308
+          'Stance' => Msf::Exploit::Stance::Passive,
+          'Passive' => true
+        )
+      )
+
+      register_advanced_options(
+        [
+          OptString.new('WritableDir', [true, 'A directory where we can write files', '']),
+          OptBool.new('CleanUpRc', [true, 'Create a cleanup resource file.', true])
+        ]
+      )
+    end
+
+    def exploit
+      run_as_background = !datastore['DisablePayloadHandler']
+      print_warning('Payload handler is disabled, the persistence will be installed only.') unless run_as_background
+
+      # Call the install_persistence function
+      # must be declared inside the persistence module
+      install_persistence
+
+      save_cleanup_rc if datastore['CleanUpRc'] && !@clean_up_rc.empty?
+
+      @persistence_service.wait if run_as_background
+    end
+
+    def install_persistence
+      # to be overloaded by the module
+    end
+
+    def save_cleanup_rc
+      host = session.sys.config.sysinfo['Computer']
+      # Create Filename info to be appended to downloaded files
+      filenameinfo = '_' + ::Time.now.strftime('%Y%m%d.%M%S')
+      logs = ::File.join(Msf::Config.log_directory, 'persistence', Rex::FileUtils.clean_path(host + filenameinfo))
+      # Create the log directory
+      ::FileUtils.mkdir_p(logs)
+
+      # logfile name
+      clean_rc = logs + ::File::Separator + Rex::FileUtils.clean_path(host + filenameinfo) + '.rc'
+      file_local_write(clean_rc, @clean_up_rc)
+
+      print_status("Meterpreter-compatible Cleaup RC file: #{clean_rc}")
+
+      report_note(host: host,
+                  type: 'host.persistance.cleanup',
+                  data: {
+                    local_id: session.sid,
+                    stype: session.type,
+                    desc: session.info,
+                    platform: session.platform,
+                    via_payload: session.via_payload,
+                    via_exploit: session.via_exploit,
+                    created_at: Time.now.utc,
+                    commands: @clean_up_rc
+                  })
+    end
+
+    def cleanup
+    end
+  end
+end

lib/msf/core/exploit/local/timespec.rb

@@ -0,0 +1,28 @@
+# -*- coding: binary -*-
+
+module Msf
+  module Exploit::Local::Timespec
+    TIMESPEC_REGEX = %r{
+    \b(
+      (?:[01]?\d|2[0-3]):[0-5]\d(?:\s?(?:AM|PM))? |            # Matches HH:MM (12h/24h)
+      midnight | noon | teatime | now |                        # Matches special keywords
+      now\s?\+\s?\d+\s?(?:minutes?|hours?|days?|weeks?) |      # Matches relative times
+      (?:mon|tue|wed|thu|fri|sat|sun)(?:day)? |                # Matches named days
+      (?:next|last)\s(?:mon|tue|wed|thu|fri|sat|sun)(?:day)? | # Matches next/last weekday
+      \d{1,2}/\d{1,2}/\d{2,4} |                                # Matches MM/DD/YY(YY)
+      \d{1,2}\.\d{1,2}\.\d{2,4} |                              # Matches DD.MM.YY(YY)
+      \d{6} | \d{8}                                            # Matches MMDDYY or MMDDYYYY
+    )\b
+  }xi # 'x' allows extended mode, 'i' makes it case-insensitive
+
+    #
+    # Attempts to validate a timespec.
+    #
+    # @param timespec [String] The timespec to test
+    # @return [Boolean] If the timespec is valid or not
+    #
+    def self.valid_timespec?(timespec)
+      !!(timespec =~ TIMESPEC_REGEX) # Ensures true/false return
+    end
+  end
+end

lib/msf/core/post/linux/user.rb

@@ -0,0 +1,22 @@
+# -*- coding: binary -*-
+
+module Msf
+  class Post
+    module Linux
+      module User
+        include ::Msf::Post::Common
+        #
+        # Returns a string of the user's home directory
+        #
+        def get_home_dir(user)
+          cmd_exec("grep '^#{user}:' /etc/passwd | cut -d ':' -f 6").chomp
+          # could also be: "getent passwd #{user} | cut -d: -f6"
+        end
+        # User
+      end
+      # Linux
+    end
+    # Post
+  end
+  # Msf
+end

spec/lib/msf/core/exploit/local/timespec_spec.rb

@@ -0,0 +1,42 @@
+require 'spec_helper'
+
+RSpec.describe Msf::Exploit::Local::Timespec do
+  describe '.valid_timespec?' do
+    it 'returns true for military time' do
+      expect(Msf::Exploit::Local::Timespec.valid_timespec?('14:30')).to eq(true)
+    end
+
+    it 'returns true for 12hr time' do
+      expect(Msf::Exploit::Local::Timespec.valid_timespec?('2:15 PM')).to eq(true)
+    end
+
+    it 'returns true for midnight' do
+      expect(Msf::Exploit::Local::Timespec.valid_timespec?('midnight')).to eq(true)
+    end
+
+    it 'returns true for now' do
+      expect(Msf::Exploit::Local::Timespec.valid_timespec?('now')).to eq(true)
+    end
+
+    it 'returns true for now plus time' do
+      expect(Msf::Exploit::Local::Timespec.valid_timespec?('now + 10 minutes')).to eq(true)
+    end
+
+    it 'returns true for relative days' do
+      expect(Msf::Exploit::Local::Timespec.valid_timespec?('next Monday')).to eq(true)
+      expect(Msf::Exploit::Local::Timespec.valid_timespec?('last Friday')).to eq(true) # unlikely to ever be used for our context
+    end
+
+    it 'returns true for mm/dd/yy based date' do
+      expect(Msf::Exploit::Local::Timespec.valid_timespec?('07/04/23')).to eq(true)
+    end
+
+    it 'returns true for mmddyy based date' do
+      expect(Msf::Exploit::Local::Timespec.valid_timespec?('010124')).to eq(true)
+    end
+
+    it 'returns true for dd.mm.yyyy based date' do
+      expect(Msf::Exploit::Local::Timespec.valid_timespec?('31.12.2023')).to eq(true)
+    end
+  end
+end

spec/lib/msf/core/post/linux/user_spec.rb

@@ -0,0 +1,37 @@
+require 'spec_helper'
+
+RSpec.describe Msf::Post::Linux::User do
+  subject do
+    mod = ::Msf::Module.new
+    mod.extend described_class
+    mod
+  end
+
+  describe '#get_home_dir' do
+    let(:user) { 'testuser' }
+    let(:expected_command) { "grep '^#{user}:' /etc/passwd | cut -d ':' -f 6" }
+
+    context 'when the user exists' do
+      it 'returns the home directory path from /etc/passwd' do
+        expect(subject).to receive(:cmd_exec)
+          .with(expected_command)
+          .and_return("/home/testuser\n")
+
+        result = subject.get_home_dir(user)
+        expect(result).to eq('/home/testuser')
+      end
+    end
+
+    context 'when the user does not exist in /etc/passwd' do
+      it 'returns an empty string' do
+        expect(subject).to receive(:cmd_exec)
+          .with(expected_command)
+          .and_return("\n")
+
+        result = subject.get_home_dir(user)
+        expect(result).to eq('')
+      end
+    end
+
+  end
+end