Analysis of A webshell Method for pw

A webshell Method for pw

Data \ bbscache \ admin_record.php records background login and operations. Let's see how this file is operated:

Admin \ admincp. php:

$ Bbsrecordfile = D_P. "data/bbscache/admin_record.php ";
If (! File_exists ($ bbsrecordfile )){
Writeover ($ bbsrecordfile, "<? Php die;?> \ N ");
} // This if only indicates that if admin_record.php does not exist, generate

If we only edit admin_record.php? Php die;?> Delete this file :)

Let's take a look at our code and write it to admin_record.php.

Log on to http: // localhost/PHPWind_GBK_6.0RC/upload/admin. php in the background.
If you log on with an incorrect user, the following record is displayed:

| Admin | s | Logging Failed | 127.0.0.1 | 1191667510 |

So we can write our code through this, but here there is a filter that cannot be used <

Therefore, our backdoors should be kept as follows: <? Php die;?> Change to <? Php/* die;?>