如何找到PHP后门隐藏技巧

可以通过一些关键字或者正则来进行匹配
(\$_(GET|POST|REQUEST)\[.{0,15}\]\(\$_(GET|POST|REQUEST)\[.{0,15}\]\))',
'(base64_decode\([\'"][\w\+/=]{200,}[\'"]\))',
'eval\(base64_decode\(',
'(eval\(\$_(POST|GET|REQUEST)\[.{0,15}\]\))',
'(assert\(\$_(POST|GET|REQUEST)\[.{0,15}\]\))',
'(\$[\w_]{0,15}\(\$_(POST|GET|REQUEST)\[.{0,15}\]\))',
'(wscript\.shell)',
'(gethostbyname\()',
'(cmd\.exe)',
'(shell\.application)',
'(documents\s+and\s+settings)',
'(system32)',
'(serv-u)',
'(提权)',
'(phpspy)',
'(后门)',
'(webshell)',
'(Program\s+Files)'