IP over DNS

Sometimes while you are performing a penetration test, you need to break out from a supposedly isolated network like an internal VLAN in a bank, or a process network full of SCADA equipment. Such networks should be completely isolated from the Internet, so there is no chance that someone who has network access can implant a backdoor and either sneak out information or allow access from the outside. This article demonstrates how the often overlooked DNS service can be used to build a covert channel and why when you configure an isolated network, you shouldn’t allow even name resolution of external hosts. To demonstrate this we will use the NSTX tunnel software to build a dns tunnel and bypass firewall. . . . → Read More: IP over DNS

DTP - Share it

The one thing that is always overlooked, when someone tries to secure a network, is the user side. It is rare to see a DMZ network, that is protected by a firewall from the users. The general idea is that if you are an internal user, you have legitimate access to the servers, so there is no need to protect them from you. In this article we will discuss a frequently overlooked feature of Cisco switches called DTP, we will explain why is it dangerous and what are the steps to disable it. . . . → Read More: DTP – Share it

GnuPG - quick console guide

This short gpg howto demonstrates how to use the Gnu Privacy Guard (GnuPG) tools on Unix/Linux systems. By following this guide you will understand how to generate a gpg key and you will go through the basics of public key encryption and digital signatures, and you would be able to work your way out to sending encrypted email attachments. . . . → Read More: GnuPG – quick console guide

Wireless WEP (in)security

Wireless security has been a great concern for the IT security professionals from at least a decade. It is difficult to protect something that you can’t see, that goes through walls and that everyone close enough can eavesdrop, especially when the only wifi security in place is the deprecated wireless encryption protocol WEP. In this article we will break the wireless security of a demo network and we will obtain the wep key. We will use arp injection in order to facilitate this so called wep crack and we will do that so fast, that from now on you will always have second thoughts about wifi security. . . . → Read More: Wireless WEP (in)security