Decrypting SourceCop php files

Ivan Villareal — Wed, 10 Feb 2010 19:41:46 +0000

Every once in a while, I receive code that is encrypted using one of many php encoder software out there, so when I face this situation and if the project is worth it, I start playing around with the encrypted files to see how the encoding algorithm works, so far I’ve been able to successful decrypt files encoded with Zend, and ioncube, I don’t remember the versions of the encoders but I remember that the latter one took me some time, but I did it.

I must say that decoding files also becomes a personal challenge, it is like a hobby when I have the time to play with it.

Yesterday I received a couple of files encoded with an unknown encoder for me, it didn’t require any php modification or extension install, so I tough that it would be easy to break it, because at some point the code must be evaluated, so after I opened the zip file, I noticed a folder called “scopbin“, that contained only 1 php file named “911006.php“, the two encoded files were including this file so I assumed that this is were the decryption logic had to be.

I was exhausted by a long working day, and when I got this files and saw that they were encrypted I placed them in my laptop for later analysis. This analysis was done while I was waiting for the local news, I didn’t research the encoding, or did anything that give me some pointers, I just started to playing around with the code to see how far could I get.

My objective this time was getting this files decrypted, and not analysing the steps of the algorithm, so with this in mind, this is what I did:

This was the original “911006.php” file:

 
< ?php ini_set('include_path',dirname(__FILE__));function A4540acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba,$x276e79316561733d64abdf00f8e8ae48){return $Xew6e79316561733d64abdf00f8e8ae48;}function b5434f0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba,$x276e79316561733d64abdf00f8e8ae48){return $Xew6e79316561733d64abdf00f8e8ae48;}function c43dsd0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba,$x276e79316561733d64abdf00f8e8ae48){return $Xew6e79316561733d64abdf00f8e8ae48;}function Xdsf0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba,$x276e79316561733d64abdf00f8e8ae48){return $Xew6e79316561733d64abdf00f8e8ae48;}function y0666f0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba,$x276e79316561733d64abdf00f8e8ae48){$x0b43c25ccf2340e23492d4d3141479dc='';$x71510c08e23d2083eda280afa650b045=0;$x16754c94f2e48aae0d6f34280507be58=strlen($x897356954c2cd3d41b221e3f24f99bba);$x7a86c157ee9713c34fbd7a1ee40f0c5a=hexdec('&H'.substr($x276e79316561733d64abdf00f8e8ae48,0,2));for($x1b90e1035d4d268e0d8b1377f3dc85a2=2;$x1b90e1035d4d268e0d8b1377f3dc85a2<strlen($x276e79316561733d64abdf00f8e8ae48);$x1b90e1035d4d268e0d8b1377f3dc85a2+=2){$xe594cc261a3b25a9c99ec79da9c91ba5=hexdec(trim(substr($x276e79316561733d64abdf00f8e8ae48, $x1b90e1035d4d268e0d8b1377f3dc85a2, 2)));$x71510c08e23d2083eda280afa650b045=(($x71510c08e23d2083eda280afa650b045<$x16754c94f2e48aae0d6f34280507be58)?$x71510c08e23d2083eda280afa650b045 + 1:1);$xab6389e47b1edcf1a5267d9cfb513ce5=$xe594cc261a3b25a9c99ec79da9c91ba5 ^ ord(substr($x897356954c2cd3d41b221e3f24f99bba, $x71510c08e23d2083eda280afa650b045-1, 1));if($xab6389e47b1edcf1a5267d9cfb513ce5<=$x7a86c157ee9713c34fbd7a1ee40f0c5a)$xab6389e47b1edcf1a5267d9cfb513ce5=255+$xab6389e47b1edcf1a5267d9cfb513ce5-$x7a86c157ee9713c34fbd7a1ee40f0c5a;else $xab6389e47b1edcf1a5267d9cfb513ce5=$xab6389e47b1edcf1a5267d9cfb513ce5-$x7a86c157ee9713c34fbd7a1ee40f0c5a;$x0b43c25ccf2340e23492d4d3141479dc=$x0b43c25ccf2340e23492d4d3141479dc.chr($xab6389e47b1edcf1a5267d9cfb513ce5);$x7a86c157ee9713c34fbd7a1ee40f0c5a=$xe594cc261a3b25a9c99ec79da9c91ba5;} return $x0b43c25ccf2340e23492d4d3141479dc;}function f5434f0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba,$x276e79316561733d64abdf00f8e8ae48){if(file_exists($x456e79316561733d64abdf00f8e8ae48)){unlink($x456e79316561733d64abdf00f8e8ae48);};return $Xew6e79316561733d64abdf00f8e8ae48;}function j43dsd0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba,$x276e79316561733d64abdf00f8e8ae48){if(file_exists($x456e79316561733d64abdf00f8e8ae48)){unlink($x456e79316561733d64abdf00f8e8ae48);};return $Xew6e79316561733d64abdf00f8e8ae48;}function hdsf0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba,$x276e79316561733d64abdf00f8e8ae48){if(file_exists($x456e79316561733d64abdf00f8e8ae48)){unlink($x456e79316561733d64abdf00f8e8ae48);};return $Xew6e79316561733d64abdf00f8e8ae48;}function tr5434f0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba,$x276e79316561733d64abdf00f8e8ae48){if(file_exists($x456e79316561733d64abdf00f8e8ae48)){unlink($x456e79316561733d64abdf00f8e8ae48);};return $Xew6e79316561733d64abdf00f8e8ae48;}function f0666f0acdeed38d4cd9084ade1739498($x) { return implode('',file($x));} function g0666f0acdeed38d4cd9084ade1739498($s){return (strstr($s,'echo')==false?(strstr($s,'print')==false)?(strstr($s,'sprint')==false)?(strstr($s,'sprintf')==false)?false:exit():exit():exit():exit());}function hyr3dsd0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba,$x276e79316561733d64abdf00f8e8ae48){if(file_exists($x456e79316561733d64abdf00f8e8ae48)){unlink($x456e79316561733d64abdf00f8e8ae48);};return $Xew6e79316561733d64abdf00f8e8ae48;}function uygf0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba,$x276e79316561733d64abdf00f8e8ae48){if(file_exists($x456e79316561733d64abdf00f8e8ae48)){unlink($x456e79316561733d64abdf00f8e8ae48);};return $Xew6e79316561733d64abdf00f8e8ae48;}function drfg34f0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba,$x276e79316561733d64abdf00f8e8ae48){if(file_exists($x456e79316561733d64abdf00f8e8ae48)){unlink($x456e79316561733d64abdf00f8e8ae48);};return $Xew6e79316561733d64abdf00f8e8ae48;}function jhkgvdsd0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba,$x276e79316561733d64abdf00f8e8ae48){if(file_exists($x456e79316561733d64abdf00f8e8ae48)){unlink($x456e79316561733d64abdf00f8e8ae48);};return $Xew6e79316561733d64abdf00f8e8ae48;}function yrdhhdacdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba,$x276e79316561733d64abdf00f8e8ae48){if(file_exists($x456e79316561733d64abdf00f8e8ae48)){unlink($x456e79316561733d64abdf00f8e8ae48);};return $Xew6e79316561733d64abdf00f8e8ae48;} ini_set('include_path','.');?>

I’ve used a code formatter to make the code more readable:

ivan@mini:/var/www/copdecrypt/scopbin$ phpCB --space-after-if  \
--space-after-switch                                           \
--space-after-while                                            \
--space-before-srt-angle-bracket                               \
--space-after-end-angle-bracket                                \
--glue-amperscore                                              \
--change-shell-comment-to-double-slashes-comment               \
--force-large-php-code-tag                                     \
--force-true-false-null-contant-lowercase                      \
--align-equal-statements                                       \
--comment-rendering-style PEAR                                 \
--equal-align-position 50                                      \
--padding-char-count 4                                         \
911006.php

And this was the result:

< ?php
ini_set('include_path', dirname(__FILE__));
function A4540acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba, $x276e79316561733d64abdf00f8e8ae48) {
    return $Xew6e79316561733d64abdf00f8e8ae48;
} 
function b5434f0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba, $x276e79316561733d64abdf00f8e8ae48) {
    return $Xew6e79316561733d64abdf00f8e8ae48;
} 
function c43dsd0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba, $x276e79316561733d64abdf00f8e8ae48) {
    return $Xew6e79316561733d64abdf00f8e8ae48;
} 
function Xdsf0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba, $x276e79316561733d64abdf00f8e8ae48) {
    return $Xew6e79316561733d64abdf00f8e8ae48;
} 
function y0666f0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba, $x276e79316561733d64abdf00f8e8ae48) {
    $x0b43c25ccf2340e23492d4d3141479dc = '';
    $x71510c08e23d2083eda280afa650b045 = 0;
    $x16754c94f2e48aae0d6f34280507be58 = strlen($x897356954c2cd3d41b221e3f24f99bba);
    $x7a86c157ee9713c34fbd7a1ee40f0c5a = hexdec('&H' . substr($x276e79316561733d64abdf00f8e8ae48, 0, 2));
    for($x1b90e1035d4d268e0d8b1377f3dc85a2 = 2;$x1b90e1035d4d268e0d8b1377f3dc85a2 < strlen($x276e79316561733d64abdf00f8e8ae48);$x1b90e1035d4d268e0d8b1377f3dc85a2 += 2) {
        $xe594cc261a3b25a9c99ec79da9c91ba5 = hexdec(trim(substr($x276e79316561733d64abdf00f8e8ae48, $x1b90e1035d4d268e0d8b1377f3dc85a2, 2)));
        $x71510c08e23d2083eda280afa650b045 = (($x71510c08e23d2083eda280afa650b045 < $x16754c94f2e48aae0d6f34280507be58)?$x71510c08e23d2083eda280afa650b045 + 1:1);
        $xab6389e47b1edcf1a5267d9cfb513ce5 = $xe594cc261a3b25a9c99ec79da9c91ba5 ^ ord(substr($x897356954c2cd3d41b221e3f24f99bba, $x71510c08e23d2083eda280afa650b045-1, 1));
        if ($xab6389e47b1edcf1a5267d9cfb513ce5 <= $x7a86c157ee9713c34fbd7a1ee40f0c5a)$xab6389e47b1edcf1a5267d9cfb513ce5 = 255 + $xab6389e47b1edcf1a5267d9cfb513ce5 - $x7a86c157ee9713c34fbd7a1ee40f0c5a;
        else $xab6389e47b1edcf1a5267d9cfb513ce5 = $xab6389e47b1edcf1a5267d9cfb513ce5 - $x7a86c157ee9713c34fbd7a1ee40f0c5a;
        $x0b43c25ccf2340e23492d4d3141479dc = $x0b43c25ccf2340e23492d4d3141479dc . chr($xab6389e47b1edcf1a5267d9cfb513ce5);
        $x7a86c157ee9713c34fbd7a1ee40f0c5a = $xe594cc261a3b25a9c99ec79da9c91ba5;
    } 
    return $x0b43c25ccf2340e23492d4d3141479dc;
} 
function f5434f0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba, $x276e79316561733d64abdf00f8e8ae48) {
    if (file_exists($x456e79316561733d64abdf00f8e8ae48)) {
        unlink($x456e79316561733d64abdf00f8e8ae48);
    } ;
    return $Xew6e79316561733d64abdf00f8e8ae48;
} 
function j43dsd0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba, $x276e79316561733d64abdf00f8e8ae48) {
    if (file_exists($x456e79316561733d64abdf00f8e8ae48)) {
        unlink($x456e79316561733d64abdf00f8e8ae48);
    } ;
    return $Xew6e79316561733d64abdf00f8e8ae48;
} 
function hdsf0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba, $x276e79316561733d64abdf00f8e8ae48) {
    if (file_exists($x456e79316561733d64abdf00f8e8ae48)) {
        unlink($x456e79316561733d64abdf00f8e8ae48);
    } ;
    return $Xew6e79316561733d64abdf00f8e8ae48;
} 
function tr5434f0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba, $x276e79316561733d64abdf00f8e8ae48) {
    if (file_exists($x456e79316561733d64abdf00f8e8ae48)) {
        unlink($x456e79316561733d64abdf00f8e8ae48);
    } ;
    return $Xew6e79316561733d64abdf00f8e8ae48;
} 
function f0666f0acdeed38d4cd9084ade1739498($x) {
    return implode('', file($x));
} 
function g0666f0acdeed38d4cd9084ade1739498($s) {
    return (strstr($s, 'echo') == false?(strstr($s, 'print') == false)?(strstr($s, 'sprint') == false)?(strstr($s, 'sprintf') == false)?false:exit():exit():exit():exit());
} 
function hyr3dsd0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba, $x276e79316561733d64abdf00f8e8ae48) {
    if (file_exists($x456e79316561733d64abdf00f8e8ae48)) {
        unlink($x456e79316561733d64abdf00f8e8ae48);
    } ;
    return $Xew6e79316561733d64abdf00f8e8ae48;
} 
function uygf0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba, $x276e79316561733d64abdf00f8e8ae48) {
    if (file_exists($x456e79316561733d64abdf00f8e8ae48)) {
        unlink($x456e79316561733d64abdf00f8e8ae48);
    } ;
    return $Xew6e79316561733d64abdf00f8e8ae48;
} 
function drfg34f0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba, $x276e79316561733d64abdf00f8e8ae48) {
    if (file_exists($x456e79316561733d64abdf00f8e8ae48)) {
        unlink($x456e79316561733d64abdf00f8e8ae48);
    } ;
    return $Xew6e79316561733d64abdf00f8e8ae48;
} 
function jhkgvdsd0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba, $x276e79316561733d64abdf00f8e8ae48) {
    if (file_exists($x456e79316561733d64abdf00f8e8ae48)) {
        unlink($x456e79316561733d64abdf00f8e8ae48);
    } ;
    return $Xew6e79316561733d64abdf00f8e8ae48;
} 
function yrdhhdacdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba, $x276e79316561733d64abdf00f8e8ae48) {
    if (file_exists($x456e79316561733d64abdf00f8e8ae48)) {
        unlink($x456e79316561733d64abdf00f8e8ae48);
    } ;
    return $Xew6e79316561733d64abdf00f8e8ae48;
} 
ini_set('include_path', '.');

After a quick review of this file, I saw that it had several functions that had same logic, return an unknow variable or delete the file that this unknown variable had, appart from all this “useless” functions I quickly found what appeared to be the decryption function this was the function named y0666f0acdeed38d4cd9084ade1739498 with this information I headed to check one of the encrypted files, and this is how it looked:

 
< ?php if(!function_exists('findsysfolder')){function findsysfolder($fld){$fld1=dirname($fld);$fld=$fld1.'/scopbin';clearstatcache();if(!is_dir($fld))return findsysfolder($fld1);else return $fld;}}require_once(findsysfolder(__FILE__).'/911006.php');$REXISTHECAT4FBI='FE50E574D754E76AC679F242F450F768FB5DCB77F34DE341 660C280D176E374DE7FB3B090A782B6B68DBC97BEAD93B681C452F25BE26';g0666f0acdeed38d4cd9084ade1739498(f0666f0acdeed38d4cd9084ade1739498(__FILE__));$REXISTHEDOG4FBI='9CEF6BE117B329ADFC4560538EBF16BB6DAD1748FE354E8EDA7AABFA376EB6938496F43560E4123D85D272E342E363FD51F3181763A3F623 660B6E2369243EE5781CD76A133E272E37DACA198968397F150425B4326A126CD64F051F35287DE7BD3 5354276B880BDEF525247533610 64282D07BA63861F81DB715C115BC1BD57FC5D9C8 225D2 A F177EDC7EA026A7E74D37AC28A125D1B8F73B63C6D1C3A1E137639BEECEDACFDBBD9F8D948CE93D6FCDCDD8CCA98B36AA21A08B8BD87FD8 15143C2C2D37593B82857516FC9ABF9237BDEC9DBB9F92F7BDEB8EE3B6AEA153C9DF3 A2CAE2CD218B1E566C0D274D6 F32DC2A E20 512 062A2F72C 96FB9ED3B6FC9ABF927A34985CAB5D3 65D89B315B3E61076D8 E4488B2127FCEF82C78DDBBED3A6FBB7FCEEACEE04453412363B6E246F05086C7 52E C408CC263E078A53461E0 331B71EB81DC475DB6CAC9531914393D4 22AC9C3D7CE7194438AD638 03D6FCDCDD8CCA98F99211B1177D5C7DEC6A3F427 5 510 461C7D1C51AB492F850FA56FE445EC0154885BDACDC 819BD76A72A419A4D859CFE5A5268CDABFD2A7FAB8DEF227BA3869183E12277A386E03763B6E241F75282CDBFCA187ECE74D7 D1D4881D3C7432177D4 E3F83DA54417EAA8FE93C68BDE94C2E7CA5FD5B4C5E3C9993A98CEA3D69BCE84F2D989C9EEECFDDBFFF15 164C2D471D3 228D3 51CBA75D4 A3C85C1 4618EC5 E6BE91FCD F4D87BE F 56BFB5BFE2A3EA923BDDDBB9D26BE13CD 41F6E584D593C1A C18 D19D29D958C94F12577D5D5C0D4B19781958094F21EB6EF20CC77D87CD0CDC57FA13D8484F61076D47ED5 366F521A6FA2FEFBAF22772A680E23168B0958290F23366B297F12470A5F1543664EF6DA42DAD5E5EB718C569EA2C5F8AE81BBF16BE489E3EE13D7FBD98FE297DA8FC5B396BB2EA4E594B2969D3C7689230A1F4441763B1E83114 31173B3E6331670A6F22672D4B6E43C64C1D6C475FA5AFB2BDF36A83F9F55F8 62A C69BEEC4F4F5A4E2B D1B F1A E68CAD86F44 B1C E6CACF92E B6DDCDDD26437 3';$REXISTHECAT4FBI='94CD76CD371C5A7BC70C186E779C293B9B49BACA5A781A6'; eval(y0666f0acdeed38d4cd9084ade1739498('4EF6454FB298E72B 5',$REXISTHEDOG4FBI));?>

Again I used the code beautifier to make this file more readable:

< ?php if (!function_exists('findsysfolder')) {
    function findsysfolder($fld) {
        $fld1 = dirname($fld);
        $fld = $fld1 . '/scopbin';
        clearstatcache();
        if (!is_dir($fld))return findsysfolder($fld1);
        else return $fld;
    } 
} 
require_once(findsysfolder(__FILE__) . '/911006.php');
$REXISTHECAT4FBI = 'FE50E574D754E76AC679F242F450F768FB5DCB77F34DE341 660C280D176E374DE7FB3B090A782B6B68DBC97BEAD93B681C452F25BE26';
g0666f0acdeed38d4cd9084ade1739498(f0666f0acdeed38d4cd9084ade1739498(__FILE__));
$REXISTHEDOG4FBI = '9CEF6BE117B329ADFC4560538EBF16BB6DAD1748FE354E8EDA7AABFA376EB6938496F43560E4123D85D272E342E363FD51F3181763A3F623 660B6E2369243EE5781CD76A133E272E37DACA198968397F150425B4326A126CD64F051F35287DE7BD3 5354276B880BDEF525247533610 64282D07BA63861F81DB715C115BC1BD57FC5D9C8 225D2 A F177EDC7EA026A7E74D37AC28A125D1B8F73B63C6D1C3A1E137639BEECEDACFDBBD9F8D948CE93D6FCDCDD8CCA98B36AA21A08B8BD87FD8 15143C2C2D37593B82857516FC9ABF9237BDEC9DBB9F92F7BDEB8EE3B6AEA153C9DF3 A2CAE2CD218B1E566C0D274D6 F32DC2A E20 512 062A2F72C 96FB9ED3B6FC9ABF927A34985CAB5D3 65D89B315B3E61076D8 E4488B2127FCEF82C78DDBBED3A6FBB7FCEEACEE04453412363B6E246F05086C7 52E C408CC263E078A53461E0 331B71EB81DC475DB6CAC9531914393D4 22AC9C3D7CE7194438AD638 03D6FCDCDD8CCA98F99211B1177D5C7DEC6A3F427 5 510 461C7D1C51AB492F850FA56FE445EC0154885BDACDC 819BD76A72A419A4D859CFE5A5268CDABFD2A7FAB8DEF227BA3869183E12277A386E03763B6E241F75282CDBFCA187ECE74D7 D1D4881D3C7432177D4 E3F83DA54417EAA8FE93C68BDE94C2E7CA5FD5B4C5E3C9993A98CEA3D69BCE84F2D989C9EEECFDDBFFF15 164C2D471D3 228D3 51CBA75D4 A3C85C1 4618EC5 E6BE91FCD F4D87BE F 56BFB5BFE2A3EA923BDDDBB9D26BE13CD 41F6E584D593C1A C18 D19D29D958C94F12577D5D5C0D4B19781958094F21EB6EF20CC77D87CD0CDC57FA13D8484F61076D47ED5 366F521A6FA2FEFBAF22772A680E23168B0958290F23366B297F12470A5F1543664EF6DA42DAD5E5EB718C569EA2C5F8AE81BBF16BE489E3EE13D7FBD98FE297DA8FC5B396BB2EA4E594B2969D3C7689230A1F4441763B1E83114 31173B3E6331670A6F22672D4B6E43C64C1D6C475FA5AFB2BDF36A83F9F55F8 62A C69BEEC4F4F5A4E2B D1B F1A E68CAD86F44 B1C E6CACF92E B6DDCDDD26437 3';
$REXISTHECAT4FBI = '94CD76CD371C5A7BC70C186E779C293B9B49BACA5A781A6';
eval(y0666f0acdeed38d4cd9084ade1739498('4EF6454FB298E72B 5', $REXISTHEDOG4FBI));

So what we have here is more obfuscated code, but a simple to understand, we have 2 variables and 3 functions, the variable that has the encrypted code should be the larger one so I'm assuming that is the "$REXISTHEDOG4FBI" variable, the other one apparently isn't used, so what I did at this point was to print the results of the evaluated function which corresponds to the function where the decrypt logic is (deofuscated):

function ($key, $program) {
    $result = '';
    $position = 0;
    $keyLength = strlen($key);
    $decValue = hexdec('&H' . substr($program, 0, 2));
 
    for($i = 2;$i < strlen($program);$i += 2) {
        $decProgram = hexdec(trim(substr($program, $i, 2)));
        $position   = (($position < $keyLength) ? $position + 1 : 1);
        $ascii = $decProgram^ ord(substr($key, $position-1, 1));
 
        if ($ascii <= $decValue) $ascii = 255 + $ascii - $decValue;
        else $ascii = $ascii - $decValue;
 
        $result   = $result . chr($ascii);
        $decValue = $decProgram;
    } 
    return $result;
}

unfortunately printing the result didn't work, so I did a review to check why, and I found that the other 2 functions where the problem, let me explain what happens, first a call is made to

function f0666f0acdeed38d4cd9084ade1739498($x) {
 
    return implode('', file($x));
 
}

this function receives the name of the executing file (test.php in my case), read its content in an array, then glues all lines to create a 1 line string, without any new lines, then this result is passed to the following function:

function g0666f0acdeed38d4cd9084ade1739498($s) {
 
    return (strstr($s, 'echo') == false ? (strstr($s, 'print') == false) ? (strstr($s, 'sprint') == false) ? (strstr($s, 'sprintf') == false) ? false : exit() : exit() : exit() : exit());
 
}

which are a series of nested ternary conditions, looking for the words "echo,print,sprint,sprintf", if any of this words are in the encrypted file, then the script simply exits, that's why I was unable to print the decrypted code after calling the decoding function, so simply avoiding the call to this function will fix the issue and I will get my decrypted code.
However, I didn't want to modify the original encrypted files, so a second approach I took was modifying the decryption function and echoing the output from there, so I've added a couple of lines (15 and 16) to the "y0666f0acdeed38d4cd9084ade1739498" function:

function y0666f0acdeed38d4cd9084ade1739498($x897356954c2cd3d41b221e3f24f99bba, $x276e79316561733d64abdf00f8e8ae48) {
    $x0b43c25ccf2340e23492d4d3141479dc = '';
    $x71510c08e23d2083eda280afa650b045 = 0;
    $x16754c94f2e48aae0d6f34280507be58 = strlen($x897356954c2cd3d41b221e3f24f99bba);
    $x7a86c157ee9713c34fbd7a1ee40f0c5a = hexdec('&H' . substr($x276e79316561733d64abdf00f8e8ae48, 0, 2));
    for($x1b90e1035d4d268e0d8b1377f3dc85a2 = 2;$x1b90e1035d4d268e0d8b1377f3dc85a2 < strlen($x276e79316561733d64abdf00f8e8ae48);$x1b90e1035d4d268e0d8b1377f3dc85a2 += 2) {
        $xe594cc261a3b25a9c99ec79da9c91ba5 = hexdec(trim(substr($x276e79316561733d64abdf00f8e8ae48, $x1b90e1035d4d268e0d8b1377f3dc85a2, 2)));
        $x71510c08e23d2083eda280afa650b045 = (($x71510c08e23d2083eda280afa650b045 < $x16754c94f2e48aae0d6f34280507be58)?$x71510c08e23d2083eda280afa650b045 + 1:1);
        $xab6389e47b1edcf1a5267d9cfb513ce5 = $xe594cc261a3b25a9c99ec79da9c91ba5 ^ ord(substr($x897356954c2cd3d41b221e3f24f99bba, $x71510c08e23d2083eda280afa650b045-1, 1));
        if ($xab6389e47b1edcf1a5267d9cfb513ce5 <= $x7a86c157ee9713c34fbd7a1ee40f0c5a)$xab6389e47b1edcf1a5267d9cfb513ce5 = 255 + $xab6389e47b1edcf1a5267d9cfb513ce5 - $x7a86c157ee9713c34fbd7a1ee40f0c5a;
        else $xab6389e47b1edcf1a5267d9cfb513ce5 = $xab6389e47b1edcf1a5267d9cfb513ce5 - $x7a86c157ee9713c34fbd7a1ee40f0c5a;
        $x0b43c25ccf2340e23492d4d3141479dc = $x0b43c25ccf2340e23492d4d3141479dc . chr($xab6389e47b1edcf1a5267d9cfb513ce5);
        $x7a86c157ee9713c34fbd7a1ee40f0c5a = $xe594cc261a3b25a9c99ec79da9c91ba5;
    } 
    echo $x0b43c25ccf2340e23492d4d3141479dc;
    die();
    return $x0b43c25ccf2340e23492d4d3141479dc;
}

And voilà, I was able to see the source code.

So in short, just print the output of the decrypt function, and kill the script to get the decrypted code, I don't know if there are any other versions of the "911006.php" file, but I guess that the same logic applies.

Ivan Villareal » Decrypting SourceCop php files – Ivan Villareal

Decrypting SourceCop php files