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How to defend against php Trojan attacks_PHP tutorial
- WBOYOriginal
- 2016-07-21 15:53:42934browse
1. Prevent jumping out of the web directory
First modify httpd.conf. If you only allow your php script program to operate in the web directory, you can also modify the httpd.conf document to limit the operation path of php. For example, if your web directory is /usr/local/apache/htdocs, then add these lines to httpd.conf:
php_admin_value open_basedir /usr/local/apache
/htdocs
In this way, if the script wants to read documents other than /usr/local/apache/htdocs, it will not be allowed. If the error display is turned on, an error like this will be prompted:
Warning: open_basedir restriction in effect. File is in wrong directory in
/usr/local/apache/htdocs/open.php on line 4
and so on.
2. Prevent php Trojan from executing webshell
Open safe_mode,
Configure in php.ini
disable_functions= passthru, exec, shell_exec, system
You can choose one of the two, or you can choose both
3. Prevent php Trojan from reading and writing the document directory
in php.ini disable_functions= passthru, exec, shell_exec, system
followed by PHP document processing functions
The main ones are
fopen, mkdir, rmdir, chmod, unlink, dir
fopen, fread, fclose, fwrite, file_exists
closedir, is_dir, readdir.opendir
fileperms.copy, unlink, delfile
That becomes
Disable_functions= passthru, exec, shell_exec, system, fopen, mkdir, rmdir, chmod, unlink, dir
, fopen, fread, fclose, fwrite, file_exists
, closedir, is_dir , readdir.opendir
, fileperms.copy, unlink, delfile
OK, we’re done, the php Trojan can’t take us anymore. Unfortunately, in this case, those things that use text databases can’t Used.
If apache is built on a windos platform, we need to pay attention to one more thing. Apache runs with system permissions by default, which is scary and makes people feel uncomfortable. Then let’s lower the permissions of apache.
net user apache fuckmicrosoft /add
net localgroup users apache /del
OK. We created a user apche that does not belong to any group.
We open the computer manager, select services, click on the properties of the apache service, we select log on, select this account, we fill in the account and password created above, restart the apache service, ok, apache is running on Low authority.
In fact, we can also configure the permissions of each folder to allow the apache user to only perform what we want him to do, and create a separate read-write user for each directory. This is also a popular configuration method used by many virtual host providers, but this method is overkill when used to prevent this.