How to remotely control computers with mail in Windows batch processing (third-party batch processing)

Recently, I saw a new method of using emails online, as the title was found. I downloaded several of these software and found that several of them were either not easy to use or incomplete functions. I searched on the blog park and saw that there are implementations using Java and python. Here we use batch processing implementations of Windows.
The most basic function we want to implement is naturally to execute the cmd command. With this, everything else is easy to say.

Advantages of Windows Batch Processing:
1. A batch file, combined with third-party batch processing, can be run directly on almost all Windows computers.
2. The code is easy to write, the logic is relatively simple, and basically it is cmd command.
Disadvantages of batch processing:
1. We control remotely, and the commands sent by email are also commands. Due to the preprocessing mechanism of Windows command interpretation, the original batch command and the sent command (variable) will be mixed together. Here we will involve space issues, quotes, escape issues, etc. that are not very complicated but are always dizzy.
2. If the above step is not handled properly, syntax errors are likely to occur. If it is a lighter error, the command completion can also return an errorlevel to you. If it is a serious syntax error, it may directly cause the command line to crash. (There is nothing.) This problem is most likely to occur with the for and if commands.

1. Send and receive emails

Windows does not come with a program that can send and receive emails through the command line, so our program needs to come with a third-party command line. Here we use toolsgetmailCome to receive emails. getmail uses the pop3 protocol, which can download emails as txt and download its attachments.
Use the emailsblatconduct. blat uses SMTP to send emails, and also supports uploading attachments.
Can be entered--helpor/?To get their detailed usage, you canRefer to this articleorRefer to this article. Although the translation is not very professional. Let me explain it briefly below.

How to receive emails in getmail

We use not every parameter in the help file. The following are several used in this example.

-u <userid>Specify the login email account
-pw <password>Login password. In China, the common email addresses do not use email account passwords to directly serve as pop3/imap passwords. You usually need to go to the settings page to obtain them yourself.
-s <server>pop3 server. You can find it on the settings page of each email.
-deleteDelete the downloaded email after downloading. If this parameter is not added, it will not be deleted.
-xtractDownload the attachments that the email has and decode the plain text of the email content. Without adding this parameter, the attachment will not be downloaded, nor will the plain text be decoded. Only an MSG file will be downloaded, containing the information about the attachment, and the string obtained by the email content after base64 encoding is saved.
-headersonlyOnly download email header information, namely sender, receiver, email subject, etc. This will theoretically speed up the acquisition.
-n <n>Get n emails in total. It seems to be counting from the earliest email I received.

getmail can also write configurations to the registry, and use configurations in the registry every time in the future, which can simplify parameters, but I didn't use them this time.
Therefore, after we configure the above parameters, the echo obtained is as follows (there is no email on the server this time):

Failed to open registry key for GetMail profile , using default.
Failed to open registry key for GetMail
Getting *********@'s mailbox contents from server :110
There are 0 messages on the server.

Use of blat emails

There are many parameters. If you want to see the details, you can also visit the page mentioned above. This is only the one you will use.

<filename>Write the first parameter directly after the command, specify a text file, and the contents of the message will be used as the contents of the message.
If you do not want to send content from the file, enter only the above parameter-, you can add a parameter to the following-body "<Email Content>"。
-to <address>The recipient's email address.
-charset <cs>Text encoding. In order to correctly send Chinese, we fixed the parameter to add-charset gbkSpecifies to use GBK encoding.
-subjectThe subject of the email.
-serverEnter the smtp server address and can be found in the email settings interface.
-fFrom, specify the email address used to send the login.
-uUsername to log in to your email address. Most of them are the part before your email address @. If the login is not successful, please search for the help interface of your email address.
-pwLogin password. The same password as the getmail above.
-attachAttach attachment to the mail.

2. Email address used by the computer

Our strategy is that the computer uses an email address independently, and you can use other email addresses to send messages to this address to achieve control.
I recommend that the computer use Sina email, which can register multiple independent email addresses with a mobile phone number. Moreover, the connection is relatively stable, and there are few cases of unsuccessful acquisition/send. The 5s email acquisition interval is stress-free and will not be blocked.
There are almost no restrictions on the email address of the sender, but the DingTalk's own DingTalk cannot be used here because the subject of the email will be encrypted together (or it uses utf8 encoding, which can't be remembered). It is more troublesome to read the batch directly. The ones that have been tried and used are Alibaba Email and QQ Email. 163 should be easy to use, but I haven't tried it.

3. Overview of principles

3.1 Execute the command

Since the subject is not encrypted in the text file received by getmail, the content is encoded by base64. So the initial plan was to only read the subject and put all the commands in the subject.
The first function that the program needs to implement is to execute the cmd command. We will add several custom functions later, and we need to specify the functions we selected here through commands. My implementation method here is to use #number to separate it, and the function selection is wrapped with the first #, and the added parameters are placed after the second #. In batch processing, you can use the for command to get these two strings separately.
For example, we name the function of executing the cmd commandcmd, commands need to be executedstart
Then the subject of our email will be entered as:#cmd#start
After this email is downloaded by getmail, the line that appears in the file is:Subject: #cmd#start
We interpret the input through for:

echo off
for /f "tokens=2,* delims=#" %%i in ('type  ^| findstr /b Subject:') do (
	set mode=%%i
	set para="%%j"
	)
echo mode:%mode%
echo command:%para%
pause

Get the result:

mode:cmd
command:"start "

Then we call cmd to execute this command. It is best to open a new cmd here. Add min to minimize running.

start /MIN  /c %para%

We can also call another bat file, which will also open a new cmd window. At the same time, some commands can be written and executed together. Echoes can also be input into the file and sent out using blat, so that echoes can be seen on the email side.

At the same time, it is best to open a new batch operation when executing other functions. In this way, if the execution of commands takes a long time, or the executed commands are running in the background, the process of checking emails will not be blocked, and other commands can still be executed by email.

3.2 File transfer

This is relatively simple. As long as the -xtract parameter is added to getmail, the attachment will be downloaded directly. To upload attachments using blat, we can name them as the upfile function and use if to judge%mode%, if it is upfile, another batch execution blat is called, and the sent file name is attached to-attachJust do it.
Using this function, we can also send batch files and write multiple commands to the file to achieve batch execution of commands. passstartThe command calls this batch. It should be noted that some mailboxes (such as Sina Emailbox) will automatically intercept emails such as bat extensions and other executable programs as attachments. The solution is also very simple. You can change the file extension and send it, for example, to .txt. After receiving the attachment, execute the renaming command via email, change it back to the extension, and then run it.

3.3 The commands containing Chinese

With Chinese subject, it cannot be displayed directly in msg file. For example, it will be displayed as:

Subject: =?UTF-8?B?4oCq4oCqZGltb0BhbGl5dW4uY29t4oCs4oCs?=

This way it is more troublesome to decode. The following content can be directly seen in Chinese after decoding using base64.-xtractAfter adding parameters, the content will be automatically decoded, which is more convenient. Therefore, we can enter commands in the email body and execute the program after reading it.
However, the content decoded by getmail is html (Click to view details), it is more troublesome to read text directly in this batch. There are solutions to the previous page.

3.4 Hide run

It's also relatively simple. Use the vbs command to completely hide the black box of cmd, and at the same time you can obtain UAC administrator permissions.
Here suppose we want to run:

REM Hide run only
echo set ws=("") &gt; 
echo  "%~ /start",0 &gt;&gt; 

del /f /q 
REM Hide run and get administrator permissions
ECHO SET UAC = CreateObject^(""^) &gt; 
ECHO  "", "Here you can add a parameter", "", "runas", 0 &gt;&gt; 

del /f /q

3.5 Power on and prevent shutdown

Starting and running can be achieved by setting a task plan. You can use the task scheduler to configure tasks in a windowed manner, or you can use the schtasks command to write a batch to implement one-click addition of tasks. At the same time, we can also send reminder emails when the program starts to monitor the startup time.

rem The batch file that needs to be started here is
set file='%~'
schtasks /Create /SC ONLOGON /TN \Windows\MailService /TR "%file%" /F /RL HIGHEST /DELAY 0001:00
rem Delay startup is used to prevent the computer from failing to send the boot email.
pause

Regarding the issue of preventing processes from being killed, welcomeClick here,orrefer to。

3.6 Configuration File

Since many different batch files need to accept/send emails, we need to write the email address, login username, and password into a configuration file to facilitate email sending and receiving. Of course, you can also use programs to store configurations in the registry function.
In the configuration file, we only need to write different configurations to a separate line and read them separately using batch processing, which also facilitates file editing.
The for command can read each line of a file and perform the same operation on each line. To use for to read the contents of a single line, you need to add a goto to the end of the execution to jump out of the for command. Use such for multiple times to read the contents of each line of the configuration file. The relevant content is visibleWeb links。

3.7 More features

We can also add more practical features throughifJudgment andgotoJump to function.
For example, we want to pop up a prompt box through the command, the code is relatively long and the input is inconvenient.

mshta vbscript:msgbox("content",64,"title")()

At this time, you can save the command to bat. Name the function popup and use if to judge%mode%Just do it. After jumping, execute the corresponding bat file and send the displayed content to bat as parameters. For example, we stipulate that $ is used as the delimiter character, and then when sending emails, enter:#popup#title$64$content
The main program separates the input according to # and determines that it needs to jump to popup; then it will receive the input:"title$64$content"
At this time, you can divide the input by dividing the input to get each part of the content and use it for pop-up windows:

echo off
for /f "tokens=1,2,3 delims=$" %%i in ('echo %~1') do (
	set tit=%%i
	set num=%%j
	set text=%%k
	)
mshta vbscript:msgbox("%text%",%num%,"%tit%")()
exit

4. Final code

Because of the use of many functions, there are also many third-party and bat files placed in a program folder.

Click to view the code

All the following codes can be clicked to expand like this.

echo off
cd /d "%~dp0"
echo set ws=("") &gt; 
echo  "%~ /start",0 >>

 rem Send startup reminder email; read configuration file
 :euser
 for /f "eol=# tokens=* delims=" %%i in () do (
    set euser=%%i
	goto ename
	)
:ename
for /f "eol=# skip=4 tokens=* delims=" %%i in () do (
    set ename=%%i
	goto epw
	)
:epw
for /f "eol=# skip=6 tokens=* delims=" %%i in () do (
    set epw=%%i
	goto smtp
	)
:smtp
for /f "eol=# skip=10 tokens=* delims=" %%i in () do (
    set smtp=%%i
	goto eto
	)
:eto
for /f "eol=# skip=12 tokens=* delims=" %%i in () do (
    set eto=%%i
	goto getcfgend
	)
:getcfgend
set subj="[MailCTRL]%DATE% %TIME% %COMPUTERNAME%"
echo host has started.&gt;
echo for more info:&gt;&gt; 
echo date and time:%DATE% %TIME%&gt;&gt; 
echo computer:%COMPUTERNAME%&gt;&gt; 
echo userdomain:%USERDOMAIN%&gt;&gt; 
echo username:%USERNAME%&gt;&gt; 
echo --------------------&gt;&gt;
systeminfo &gt;&gt; 
ipconfig &gt;&gt; 
set content=
::------------------
blat %content% -to %eto% -charset gbk -subject %subj% -server %smtp% -f %euser% -u %ename% -pw %epw% 
del /f /q %content%
del /f /q 
exit

cd /d "%~dp0"
del /F /Q z*.todo
del /F /Q Extract*.out
del /F /Q html*.out
@echo off
timeout /t 3
cls
echo ""&gt; 
::echo %~dp0&gt; 
echo ##########################
echo setting email service......
:euser
for /f "tokens=* delims=" %%i in () do set cfgfile=%%~i
echo setted cfgfile:%cfgfile%
for /f "eol=# tokens=* delims=" %%i in (%cfgfile%) do (
    set euser=%%i
	goto epw
	)
:epw
for /f "eol=# skip=6 tokens=* delims=" %%i in (%cfgfile%) do (
    set epw=%%i
	goto pop
	)
:pop
for /f "eol=# skip=8 tokens=* delims=" %%i in (%cfgfile%) do (
    set pop=%%i
	goto getcfgend
	)
:getcfgend
echo service started successfully AT %DATE% %TIME%
echo ------------------------------------
:see
TIMEOUT /T 5
echo checking new messages at %TIME%
for /f "skip=3 tokens=3 delims=# " %%i in ('getmail -u %euser% -pw %epw% -s %pop% -headersonly') do set newmsg=%%i
echo new message received:%newmsg%
if %newmsg% GEQ 1 goto get
goto see
:get
set mode=
set para=
del /F /Q MSG*.TXT
del /F /Q Extract*.out
echo downloading the new messages...
getmail -u %euser% -pw %epw% -s %pop% -delete -xtract -n 1
::                                    -delete
:tell
for /f "tokens=2,* delims=#" %%i in ('type  ^| findstr /b Subject:') do (
	set mode=%%i
	set para="%%j"
	)
set htext=%RANDOM%
del /f /q html%htext%.out
echo use ------------------------
html2txt  html%htext%.out
echo ----------------------------------------
echo information read from :
echo mode: %mode%
echo command: %para%
echo html file:html%htext%.out
echo RUNNING THE PROGRAM......
::if %mode%==cmd goto directcmd
::if %mode%==back goto backcmd
::if %mode%==xcmd goto xcmd
::if %mode%==xback goto xbackcmd
if %mode%==cmd goto textcmd
if %mode%==back goto textback
if %mode%==xcmd goto textX
if %mode%==xback goto textXback
if %mode%==popup goto popup
if %mode%==poptext goto poptext
if %mode%==upfile goto upfile
if %mode%==use goto changecfg
::if %mode%==dir goto changedir
rem There are still some functions that have not been developed。There are several functions that are replaced below。
goto see
:directcmd
start /MIN  %para%
goto see
:backcmd
start /MIN  %para%
goto see
:xcmd
set xmark=%RANDOM%
echo %para%&gt; z%xmark%.todo
ECHO SET UAC = CreateObject^(""^) &gt; 
ECHO  "", "z%xmark%", "", "runas", 0 &gt;&gt; 
echo using vbs to run an admin command.

del /f /q 
goto see
:xbackcmd
set xmark=%RANDOM%
echo %para%&gt; z%xmark%.todo
ECHO SET UAC = CreateObject^(""^) &gt; 
ECHO  "", "z%xmark%", "", "runas", 0 &gt;&gt; 
echo using vbs to run an admin command.

del /f /q 
goto see
 
:textcmd
start /MIN  %htext%
goto see
:textback
start /MIN  %htext%
goto see
:textX
ECHO SET UAC = CreateObject^(""^) &gt; 
ECHO  "", "%htext%", "", "runas", 0 &gt;&gt; 
echo using vbs to run an admin command.

del /f /q 
goto see
:textXback
ECHO SET UAC = CreateObject^(""^) &gt; 
ECHO  "", "%htext%", "", "runas", 0 &gt;&gt; 
echo using vbs to run an admin command.

del /f /q 
goto see
 
:popup
start /MIN  %para%
goto see
:poptext
start /MIN  %htext%
goto see
:upfile
start /MIN  %para%
goto see
:changecfg
echo %para%&gt; 
goto euser
 
:changedir
start /MIN  %htext%
goto see

rem Used for command echo。
echo off
cd /d "%~dp0"
:euser
for /f "tokens=* delims=" %%i in () do set cfgfile=%%~i
echo setted cfgfile:%cfgfile%
for /f "eol=# tokens=* delims=" %%i in (%cfgfile%) do (
    set euser=%%i
	goto ename
	)
:ename
for /f "eol=# skip=4 tokens=* delims=" %%i in (%cfgfile%) do (
    set ename=%%i
	goto epw
	)
:epw
for /f "eol=# skip=6 tokens=* delims=" %%i in (%cfgfile%) do (
    set epw=%%i
	goto smtp
	)
:smtp
for /f "eol=# skip=10 tokens=* delims=" %%i in (%cfgfile%) do (
    set smtp=%%i
	goto eto
	)
:eto
for /f "eol=# skip=12 tokens=* delims=" %%i in (%cfgfile%) do (
    set eto=%%i
	goto getcfgend
	)
:getcfgend
for /f "tokens=* delims=" %%i in ('EnTextChange -Text:"html%"') do (
	set todo=%%i
	goto out
	)
:out
del /f /q html%
set remark=re%RANDOM%
%todo%&gt; %remark%.txt
echo -----------------------------&gt;&gt; %remark%.txt
echo the cmd you run BY ADMIN: %todo%&gt;&gt; %remark%.txt
blat %remark%.txt -to %eto% -charset gbk -subject [MailCTRL]command"%TIME%" -server %smtp% -f %euser% -u %ename% -pw %epw%
timeout /t 5
del /f /q %remark%.txt
exit

echo off
::Need to display Chinese,Please useANSIcoding
cd /d "%~dp0"
for /f "tokens=1,2,3 delims=$" %%i in ('EnTextChange -Text:"html%"') do (
set tit=%%i
set num=%%j
set text=%%k
)
::del /f /q html%
mshta vbscript:msgbox("%text%",%num%,"%tit%")()
pause
exit

rem Used to upload files
echo off
cd /d "%~dp0"
:euser
for /f "tokens=* delims=" %%i in () do set cfgfile=%%~i
echo setted cfgfile:%cfgfile%
for /f "eol=# tokens=* delims=" %%i in (%cfgfile%) do (
    set euser=%%i
	goto ename
	)
:ename
for /f "eol=# skip=4 tokens=* delims=" %%i in (%cfgfile%) do (
    set ename=%%i
	goto epw
	)
:epw
for /f "eol=# skip=6 tokens=* delims=" %%i in (%cfgfile%) do (
    set epw=%%i
	goto smtp
	)
:smtp
for /f "eol=# skip=10 tokens=* delims=" %%i in (%cfgfile%) do (
    set smtp=%%i
	goto eto
	)
:eto
for /f "eol=# skip=12 tokens=* delims=" %%i in (%cfgfile%) do (
    set eto=%%i
	goto getcfgend
	)
:getcfgend
blat - -body "The file you sent on %TIME% by %USERNAME% on computer:%COMPUTERNAME%. Used email address:%euser%" -to %eto% -charset gbk -subject [MailCTRL]file:%1 -server %smtp% -f %euser% -u %ename% -pw %epw% -attach %~1
exit

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MailCTRL Download

This is the article about Windows batch processing to realize remote control of mail (third-party batch processing). For more related content on Windows batch processing, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!