Some premium wordpress theme that we buy sometimes deliberately provided with Bytecode encoding by the developer (PHP files), examples are premuim wordpress theme that I got this.
Examples of my wordpress themes contained Bytecode decoding, for example:
<?php $_F=__FILE__;$_X='Pz48P3A5cA0KDQo3dW5jdGlvbiAwcHQ5M20zc25vMF9zM3R0aW5ncygkazN5KSB7DQoNCglnOG9iNTggJHMzdHRpbmdzOw0KDQoJMjN0dTJuICRzM3R0aW5nc1skazN5XTsNCg0KfQ0';eval(base64_decode('JF9YPWJhc2U2NF9kZWNvZGUoJF9YKTskX1g9c3RydHIo........................
base64_decode('JF9YPWJhc2U2NF9kZWNvZGUoJF9YKTskX1g9c3RydHIoJF9YLCdqd3ZhcmhlZmw4NzM5MjU0MDYnLCc2MDQ1MjkzNzhsZmVocmF2d2onKTskX1I9ZXJlZ19yZXBsYWNlKF9fRklMRV9fLCRfRiwkX1gpO2V2YWwoJF9SKTskX1I9MDskX1g9MDs=')); ?>



