Article by Dan Dieterle
Social engineering attacks are one of the top techniques used against networks today.
Why spend days, weeks or even months trying to penetrate layers of
network security when you can just trick a user into running a file that
allows you full access to their machine and bypasses
anti-virus,
firewalls and many intrusion detection systems?
This is most commonly used in phishing attacks today – craft an
e-mail, or create a fake website that tricks users into running a
malicious file that creates a backdoor into their system. But as a
security expert, how could you test this against your network? Would
such an attack work, and how could you defend against it? (click image to enlarge)
The Backtrack Linux penetration testing platform includes one of the
most popular social engineering attack toolkits available. My previous
“How-To” on Backtrack 4′s SET has been extremely popular. Well,
Backtrack 5′s SET includes a whole slew of new features and I figured it
was time to update the tutorial.
We will use SET to create a fake website that offers a backdoored program to any system that connects. So here goes…
Okay, timeout for a disclaimer: This is for security testing purposes
only, never attempt to use any security checks or tools on a network
that you do not have the authorization and written permission to do so.
Doing so could cost you your job and you could end up in jail.
1. Obtain Backtrack 5 release 1. You can use the LiveCD version, install it on a new system or run it in a Virtual Machine.
2. The first thing you will want to do is update both the Metasploit
Framework and the Social Engineering Toolkit to make sure you have the
latest version. Update both, restart SET and check updates one more
time.
3. Select number 1, “Social Engineering Attacks”
4. Next select 2, “Website Attack Vectors”. Notice the other options available.
5. Then 1, “Java Applet Attack Method”. This will create a Java app that has a backdoor shell in it.
6. Next choose 1, “Web Templates” to have SET create a generic
webpage to use. Option 2, “Site Cloner” allows SET to use an existing
webpage as a template for the attack webpage.
7. Now choose 1, “Java Required”. Notice the other social media options available.
8. Pick a payload you want delivered, I usually choose 2, “Windows
Reverse_TCP Meterpreter”, but you have several to choose from including
your own program . Number 13, “ShellCodeExec Alphanum Shellcode” is interesting as it runs from memory, never touching the hard drive, thus effectively by-passing most anti-virus programs.
9. Next choose an encoding type to bypass anti-virus.
“Shikata_ga_nai” is very popular, Multi-Encoder uses several encoders,
but number 16 is best, “Backdoored Executable”. It adds the backdoor
program to a legitimate program, like Calc.exe.
10. Set the port to listen on, I just took the default.
Now Backtrack is all set and does several things. It creates the
backdoor program, encodes and packs it. Creates the website that you
want to use and starts up a listening service looking for people to
connect. When done, your screen will look like this (click image to enlarge):
Okay we are all set. Now if we go to a “Victim” machine and surf to the IP address of the “attacker” machine we will see this (click image on the left below to enlarge):
If the “Victim” allows this Java script to run, we get a remote session on our attacking machine (click image on the right above to enlarge):
You now have access to the victims PC. Use “Sessions -i” and the
Session number to connect to the session. Once connected, you can use
linux commands to browse the remote PC, or running “shell” will give you
a remote windows command shell. (click image to enlarge)
That’s
it, one bad choice on the victim’s side and security updates and
anti-virus means nothing. The “Victim” in this case was a fully updated
Windows XP Professional with the top name anti-virus internet security
suite installed and updated.
They can even surf away or close the webpage, because once the shell
has connected the web browser is no longer needed. Most attackers will
then solidify their hold on the PC and merge the session into another
process effectively making the shell disappear.
This is why informing your users about the dangers of clicking on
unknown links in e-mails, suspicious web links, online anti-virus
messages and video codec updates is critical. It can be very hazardous
to your network.
The easiest way to stop this type of attack is to simply run the
FireFox add-in “Noscript”, also BitDefender AV 2012 seems very, very
resilient against these types of attacks.
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