NetRipper – Smart traffic sniffing for penetration testers

Ionut

Ionut Popescu, Senior Security Consultant @ KPMG Romania has been accepted as speaker at the prestigious DEFCON conference. He will present one of his projects: NetRipper tool, developed especially to be used in penetration testing projects.

The conference will be held in Las Vegas, Nevada, between 6-9 August 2015.

NetRipper – Short description

The post-exploitation activities in a penetration test can be challenging if the tester has low-privileges on a fully patched, well configured Windows machine. This work presents a technique for helping the tester to find useful information by sniffing network traffic of the applications on the compromised machine, despite his low-privileged rights. Furthermore, the encrypted traffic is also captured before being sent to the encryption layer, thus all traffic (clear-text and encrypted) can be sniffed. The implementation of this technique is the tool called NetRipper which uses API hooking to do the actions mentioned above and which has been especially designed to be used in penetration tests, but the concept can also be used to monitor network traffic of employees or to analyze a malicious application.

https://www.defcon.org/html/defcon-23/dc-23-speakers.html#Popescu

And we will be waiting to share  his experience at the conference in the next article.

Mobile penetration testing on Android using Drozer

Android red logoMobile phones have become an indispensable part of our daily life. We use mobile phones to communicate with our loved ones, for quick access to information through the Internet, to make transactions through mobile banking apps or to relax reading a good book.

In a way, a big part of our private life has moved into the digital environment. Mobile phones seem to be a pocket-sized treasure of secrets and information, hiding our most valuable photos, mails, contacts and even banking information. There’s no wonder why we need mobile phones to have bullet-proof security.

Android is the most common operating system for mobile devices and is particularly interesting from the security point of view.  It is very permissive, allowing its users to customize about anything, administrative privileges (a.k.a. rooting) can be unlocked on most phones, it has a very fuzzy system for the permissions required by applications and it features different ways for one application to interact with other applications.

In this blog post, we are going to focus on how Android apps can interact with each other and how the security of those interactions can be tested.

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Hacknet 2015

Map-God1KPMG Europe’s internal information security conference – Hacknet, was held in Berlin and lasted two days, the 29th and the 30th of April.

This year, it was Ionut, Daniel and me who had the privilege of representing KPMG Romania.

Our team arrived in Berlin on the 28th. After taking our luggage to the hotel, we went for dinner, followed by a short walk in the city.

First Day

The conference kicked off early on the 29th and the program for the day consisted of three presentations and the CTF competition.

First presentation was on Relaying Contactless EMV, by a colleague from KPMG NL. After an introduction to smart-cards and EMV, the speaker described the concept of Relay Attacks on Contactless Transactions. Afterwords, he showed a video illustrating his Android implementation of the attack, the novelty of his approach being the small time overhead incurred by the relay. Measurements showed that the duration of a relayed transaction was very close to the duration of a native transaction (sometimes, due to optimizations, even faster). Continue reading

Writing a Metasploit post exploitation module

Metasploit framework logoThe exploitation of a machine is only one step in a penetration test. What do you do next? How can you pivot from the exploited machine to other machines in the network? This is the phase where you need to prove your post exploitation skills. Even if Metasploit is a complex framework, it is not complete and it sometimes needs to be extended.

Why would I write such a module?

Metasploit is the “World’s most used penetration testing software”, it contains a huge collection of modules, but it is not complete and you can customize it by writing your own modules.

Even if you manage to compromise a machine, you may ask yourself: “Now what?”. You can use one of the many Metasploit post exploitation modules, but what if you don’t find a suitable module for you? You may request it to the Metasploit community and developers but it may take a lot of time until it will be available. So why don’t you try to write your own module?

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Penetration Testing or Vulnerability Assessment – Which one should I choose?

penetration testing or vulnerability assessmentIn this post we will take a quick look at the differences between vulnerability assessment (VA) and penetration testing (PT). Furthermore, we’ll give a set of questions that should help you decide which service is the best choice for your particular case.

So let’s say you want to improve the security of your internal network infrastructure and you have to choose between VA and PT – offered by your favorite consultancy firm. First of all, let’s see what they are.

Vulnerability Assessment – is the process of identifying and prioritizing technical vulnerabilities which affect a target system or network. It is mainly done automatically using a vulnerability scanner and it’s usually aimed at a wide area of machines. The purpose of a VA is to find as many vulnerabilities as possible in the given time frame. Optionally, manual validation may be included for the critical findings but this is not usually done when a high number of vulnerabilities are involved.

Penetration Testing – is a goal-based simulation of a real attack. The pentesters will search for a chain of vulnerabilities in the target system/network and exploit them to reach their target (e.g. gain access to a client database, obtain sensitive information, gain Domain Admin, etc). The pentest report will contain only the vulnerabilities encountered during the attack against the target and no additional checks are being made. However, the reported vulnerabilities are 100% validated and their risk for the business is accurate.

Neither VA, nor PT should be confused with the security audit which is a totally different service.

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