How to identify the simple back door of inspection-free PHP

This article introduces the relevant knowledge of "how to identify a simple inspection-free PHP back door". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

One of the most common sentences may be written like this.

Or like this.

Tudouya gave [a construction skill] on FREEBUF to make use of

The copy code is as follows:

Construction generation, of course, is too intuitive to write like this.

The copy code is as follows:

Then fill in some ordinary code for camouflage, and a simple "kill-free" shell sample appears

Let's take a look at the back door of the php, which claims to be the simplest test-free kill in history.

Go directly to the code:

Password page

Recently captured a webshell sample based on PHP, its ingenious code dynamic generation, creepy own page camouflage, let us feel a lot of fun in the process of analyzing this sample. Next, let's enjoy this strange Webshell together.

The Webshell code is as follows: