feat: add source guardian exploit

Author: marcocesarato

src/Definitions.php

@@ -433,6 +433,12 @@ class Definitions
             'level' => self::LVL_WARNING,
             'pattern' => '/([\s]*\$\w+[\s]*\[[\s]*\$\w+[\s]*%[\s]*strlen[\s]*\([\s]*\$\w+\)[\s]*\][\s]*\;?[\s]*){2,}/i',
         ],
+        'source_guardian' => [
+            'description' => 'SourceGuardian is a PHP encoder often used for the obfuscation of malicious code',
+            'level' => self::LVL_DANGEROUS,
+            'pattern' => '/[;\s]*sg\_load[\s]*\([\s]*[\\\'\"][A-Za-z0-9+\/]{150,}={0,3}[\\\'\"][\s]*\)/i',
+            'link' => 'https://www.sourceguardian.com',
+        ],
     ];
 
     /**