From: Forbes

Screen capture of output from the listener (attacker side) of the Linux bash attack. Image courtesy David Schwartzberg

Data security is something that most people don’t want to think about. In our age of persistent connectivity, most data users, whether they are on a desktop, laptop or cell phone, connect to their data without thinking of the security risks of transmitting their data by connecting to a public network or an unsecured network of any kind. And most users think of data security in terms of malicious hacks on Windows and maybe a Mac once in a while. No one would ever think of screwing with Tux, he’s so cute and all, and everyone loves good old open-sourced Linux, right? Well, no, yes and yes, but . . .

I recently learned of the discovery of a Linux hack that has been developed by Mark Kitka of Viopoint, whose company performs vulnerability assessment and network penetration
testing of high-level enterprise networks with sensitive data. He is a security consultant with the company (and former Linux engineer) who is a frequent speaker at information security and hacker conferences such as SecTorCa and various BSides events, Grr Con and others.

here are many useful tools that are developed in such conferences that do not receive the press they deserve. One recent tool, for example, is a visualization system that combines the principles of offensive security, 3D data visualization, and ‘big data’ to allow users to understand the complex interconnections between websites called Web 3.0 — you can demo it here.

Kitka gave me a detailed rundown of how this Linux hack works, and what the risks are for the data security of the Linux user-base. He is what is known as a White Hat hacker, aka an “ethical hacker,” one of the good guys whose job it is to think of what are known as “penetration attacks” on company servers. His penetration testing evaluates the weakness of company data servers that are protecting valuable information technology assets such as company databases, personnel files, proprietary technology schematics and other crucial data related to the company’s intellectual property.

I asked Kitka to provide a general description of his modus operandi for indentifying a computer’s potential vulnerability and exploiting this weakness with the execution of a computer attack. Attacking a computer system is a fairly straightforward process. First, the attacker discovers as much information as possible about a potential target. This could include socially engineering the information out of people to using Nmap to identify open ports. Typically, during a malicious hack at this point, no laws have been broken; this changes during the next steps. The attacker, once the information has been gathered, proceeds to utilize this information to exploit vulnerabilities in the infrastructure, which are almost always there. Once the attacker is in the system, he or she wants to make sure that they do not lose access to that system before continuing on to attack the network from within. This stage in the attack is usually referred to as establishing persistence, or simply persistence. Knowing that this is a key step for an attacker to “own” a network, many security officers and engineers spend a lot of time attempting to prevent this from occurring. It was this concept that got me thinking about what nobody would expect.

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