Inbreken bij je buurvrouw

Je buitengesloten buurvrouw helpen in te breken in haar eigen huis, blijkt ze journalist te zijn!


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Lukt het mij om in te breken in de WiFi-verbinding van De Zaak?

Het magazine De Zaak heeft een uitgebreid artikel geplaatst waarin ik wordt geïnterviewd en waarin ik tevens ben uitgedaagd om hun WiFi te hacken. Zal het mij lukken?




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SAP security testing

In januari gaf ik een presentatie over SAP security testing tijdens een bijeenkomst van de Vereniging Nederlandse SAP Gebruikers (VNSG). Ze hebben hiervan anoniem verslag gemaakt en gepubliceerd in hun magazine. Drie keer raden wie de ethisch hacker is waar ze het over hebben ;-)


Posted in interview, SAP | 4 Comments

NOS radio-interview over datalekken

De NOS nodigde mij uit om te komen spreken over datalekken. Best eng om voor 200.000 luisteraars mijn verhaal te mogen doen!

nos 3

Posted in interview, radio | 5 Comments

How I accidentally found a huge data leak during a college lecture

A few weeks ago I gave a guest lecture at the Windesheim University of Applied Sciences in The Netherlands. Being a Windesheim graduate myself I’ve always kept in touch with my former teachers. One of them told me recently that a lot of students want to learn more about IT security & hacking and invited me to give a guest lecture. Of course! And to keep it a bit juicy, I added a hacking demonstration to my lecture.

When I started the demonstration, I thought it would be fun to ask the students to name a company of which I would subsequently review the security. What I found out next was quite astonishing and I had to change the direction of the demonstration in order to protect the company’s security.
Continue reading

Posted in responsible disclosure, security assessment | 44 Comments

Kennissessie over hacking gegeven bij Cqure

Vandaag een kennissessie over hacking gegeven bij Cqure. Erg leuk om te doen!

cqure 1 cqure 2

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Beveiliging van klantgegevens kan fikse strop voorkomen

Het blad Vastgoed interviewde mij voor hun februari oplage:


Klik op het plaatje voor een vergroting.

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Interview door Financieel Dagblad over privacy

Het Financieel Dagblad heeft mij van de week geïnterviewd over privacy en dat stuk is vandaag te lezen in de krant en tevens ook online:

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Afluisteren via een elektronische SIM-kaart

De traditionele SIM-kaart gaat vervangen worden door een digitale variant: de e-SIM. Een e-SIM heeft wat betreft software-updates veel beveiligingsvoordelen, maar geeft overheden ook een nieuwe manier om ons in de gaten te houden.

De e-SIM stelt (vooralsnog) smartphone-gebruikers vanaf juni in staat om van provider te veranderen zonder de SIM-kaart uit de telefoon te halen. Dit is een mooie feature, maar zeker een ontwikkeling die we in de gaten moeten houden. Continue reading

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Online banking security

Checkmarx interviewed me for their article ‘All You Wanted To Know About Online Banking Security’:

checkmarx 2

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NOS: “Wat vind je van de nieuwe hackersserie Mr. Robot?”

Benieuwd wat ik van de nieuwe hackersserie Mr. Robot vind? De NOS vroeg het mij:

nos 2

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Inbreken in de NOS-studio?

Dit keer is een hacker het wel gelukt om in de juiste NOS-studio te komen ;-)


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Interviewed by Lock Me Down podcast

Max McCarty from Lock Me Down podcast interviewed me for an hour (view the show notes) and we talked about web security and how software developers can improve it:

Posted in podcast, security awareness, software development, website security | 1 Comment

Zo slordig gaan bedrijven met persoonsgegevens van hun klanten om

Nieuwssite Z24 had een interview met mij en heeft hierover een uitgebreid artikel geschreven:

z24 2

Posted in interview, security awareness | 5 Comments

Interview op BNR Nieuwsradio

Vanmiddag had BNR Nieuwsradio mij uitgenodigd in hun radioprogramma over het wachtwoordlek dat ik gevonden had bij Phone House en Media Markt. De uitzending is online terug te beluisteren:


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Epic failure of Phone House & Dutch telecom providers to protect personal data: How I could access 12+ million records #phonehousegate

On September 11, 2015 I visited Media Markt in Utrecht Hoog Catherijne, a well-known electronics shop in The Netherlands. Since summer 2014, the biggest independent Dutch phone retail company Phone House also operates (white labeled) from within Media Markt locations as a store-in-a-store concept. I had a few questions about my phone subscription so I talked to a Phone House employee. We were discussing the new Samsung Galaxy S6 Edge phone and I was thinking about buying one.

Somewhere in the conversation the service & sales guy asked me what I did for a living so I told him I earned my money as a freelancer by hacking (with authorization) into computer systems of businesses and writing security reports about it. He thought that was cool so we talked a few more minutes about this subject. I even told him I had noticed some months ago that one of his Media Markt colleagues had written a password on a post-it and attached it onto a computer monitor near a cash desk, in plain sight where any customer could see it :

tn_20151003_171315(0) v3 Naamloos

As you can see, the password to unlock Media Markt computers was media321. A very strong one!

We both laughed about how irresponsible and naive that was.

The conversation continued about my desire for a new phone and about all associated kinds of subscriptions I could choose of. After about ten minutes I made up my mind and ordered a new phone and a new subscription. I’m still in shock about what happened next! Continue reading

Posted in data leakage, privacy, responsible disclosure, security assessment | 419 Comments

Scanning an enterprise organisation for the critical Java deserialization vulnerability

On November 6, security researchers of FoxGlove Security released five zero day exploits for WebSphere, WebLogic, JBoss, Jenkins and OpenNMS. These software products are used everywhere in enterprise organizations and with the published exploits remote malicious code can be unauthenticated executed.

The underlying vulnerability was known for years but it was vague and believed to be hard to exploit. That situation changed when Chris Frohoff (@frohoff) and Gabriel Lawrence (@gebl) published in January of an exploit generator for it in their talk on AppSecCali . Their generator didn’t get much attention on the internet. FoxGlove didn’t find the original (underlying) vulnerability, but they did find vulnerable products and wrote exploits for it. They call the vulnerability “the most underrated, underhyped vulnerability of “. When I read about FoxGlobe’s research on Twitter on November 8, , my guts told me immediately that this was something big. Continue reading

Posted in analysis, security vulnerability, zero day | 25 Comments

How I could hack internet bank accounts of Danish largest bank in a few minutes

In August I visited the Chaos Communication Camp near Berlin. Once every four years this great and world’s greatest hacker festival is organized. I spoke with a couple of cool Danish hackers there and we talked about internet security and eventually about the security of Danish banks. Seemed like quite a lot of Danish bank have terrible HTTPS connection security (scoring a F on Qualys SSL Labs). That’s a bad sign and my gut feeling was telling me that this wouldn’t be the only security vulnerability they would have.

So I opened up the web site of Danske Bank, one of those bank sites. I clicked thru the site and was curious to see how the HTML code looked like, so opened the code of the customer login screen of the banking environment. I scrolled thru the code to get a grasp of the technology used. Then my eye caught JavaScript comments that seemed to contain internal server information. Not just a few variables, but quite a lot of confidential data actually (!). It was in URL encoded format, so I decoded it right away. Really wondering what kind of secrets it contained.

When I decoded it, I was shocked. Is this happening for real? I was less than a minute on their web site. This is just the HTML code of the login screen, one of the most visited pages of Danske Bank’s web site. I never heard of this bank, but my new friends told me it was the biggest bank in Denmark. Continue reading

Posted in responsible disclosure, website security | 183 Comments

Full disclosure: multiple critical security vulnerabilities (including a backdoor!) in PHP File Manager

In July 2010 I was looking for a web based file manager that I could use on my own web server. After some research I found the PHP File Manager from Revived Wire Media. A basic, but good looking web based file manager for just $ 5. I bought it and installed it on a test server to see how it worked and if it was safe.

After looking at it, I did some shocking findings which I’ll disclose in this article. This commercial off the shelf software product contains several critical security vulnerabilities that can be easily unauthenticated remotely exploited. On top of that, it even includes a poorly secured backdoor, leaving this web based file manager completely open.

I’ve contacted Revived Wire Media three times but got no response of them, so I’m going full disclosure.

At this moment, confidential files can be be easily downloaded from Eneco, Nintendo, Danone, Nestle, Loreal, EON, Siemens, Vattenfall, Oxford, Hilton, T-Mobile, CBS, 3M and also a couple of banks and quite a lot of other companies (lesser known to me).

One company in America that uses the file manager is active in youth care and provides mental health and substance abuse services. It has 250 mental health professionals who are probably sharing all kinds of very confidential patient information via PHP File Manager.

Continue reading

Posted in PHP security, responsible disclosure, security assessment | 36 Comments

M-FILES radioshow: ‘Rest In Privacy’

Deze week was ik te gast in de radioshow van M-FILES wat ging over online privacy. Vanaf 22:12 minuten is mijn bijdrage te horen:

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