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About the Author:

Dejan Lukan is a security researcher for InfoSec Institute and penetration tester from Slovenia. He is very interested in finding new bugs in real world software products with source code analysis, fuzzing and reverse engineering. He also has a great passion for developing his own simple scripts for security related problems and learning about new hacking techniques. He knows a great deal about programming languages, as he can write in couple of dozen of them. His passion is also Antivirus bypassing techniques, malware research and operating systems, mainly Linux, Windows and BSD. He also has his own blog available here: http://www.proteansec.com/.

Reverse Engineering Tools

1. Introduction

First, we’re going to describe the process of compiling/assembling a source code to an executable file. This is very important, so we need to understand it when reverse […]


Fuzzing Vulnserver with Sulley: Part 3

1. Introduction

Vulnserver is a vulnerable server written by Stephen Bradshaw whose blog is located here: grey-corner. This server was written intentionally to be vulnerable, so we can learn fuzzing […]

Computer security concept.

Fuzzing Vulnserver with Peach: Part 2

1. Introduction

The vulnserver.exe server is a vulnerable server that was written specifically for fuzing purposes. Therefore the software intentionally contains vulnerabilities that we can exploit to gain control over […]


Fuzzing Vulnserver: Discovering Vulnerable Commands: Part 1

1. Introduction

Vulnserver is a Windows TCP server running on port 9999. It was written by Stephen Bradshaw whose blog is located here. The server was intentionally written to be […]


Linux TPM Encryption: Initializing and Using the TPM

1. Initializing the TPM

To secure our data we must first initialize the TPM. What we’re actually doing is changing the settings of the hardware TPM chip module on the […]


Packet Filtering

1. Packet Filtering Introduction

This tutorial will talk about packet filtering. First we must define what packet filtering is. Packet filtering is a process of allowing or blocking packets at […]


Security Categories

1. Introduction

I’ve been a security enthusiast for years now, and currently I’m working as a security penetration tester. Over the years it has happened that I’ve heard about a […]


Linux TPM Encryption: Enabling TPM in BIOS and Kernel

1. Introduction

The TPM stands for the Trusted Platform Module, which is a secure microprocessor that can store cryptographic keys that are further used to encrypt/decrypt data.

The following picture is […]


How to Use Iptables

1. Introduction

First we must mention that iptables is a Linux kernel firewall, which is why we can categorize it with the picture below:

The picture is presented so we can […]


The Browser Exploitation Framework (BeEF) – Part 2

The first article in this series can be found here: The Browser Exploitation Framework (BeEF) – Part 1.
1. Using the Modules

In this section we’ll describe all the available modules […]


The Browser Exploitation Framework (BeEF) – Part 1

1. Introduction

We can categorize the BeEF social engineering framework as shown in the picture below:

We can read more about the mentioned frameworks, namely: SET (Social Engineering Framework), BeEF, Honeyd […]


Crack Me Challenge: Final Edition

You can find the rest of the Crackme Challenge series here.

Part 6

The code for logical segment 6 is as follows:

0040181F |. B9 10000000 mov ecx,10
00401824 |. 8DB424 C0000000 lea […]


CrackMe Challenge Part 5: Logical Code Segments Continued

CrackMe Part 5: Logical Code Segments Continued
The code in logical code segment 4 additionally changes the stack at address . The code is presented here:

004017E5 |. B8 3F000000 mov […]


Crack Me Challenge Part 4

First we must take a look at the following piece of code that will be presented in the code segment 5:

004017FC |. B8 40000000 mov eax,40

00401801 |. 33C9 xor […]


WordPress Security

1. Introduction

There are numerous tools available when checking the security of the WordPress Content Management System (CMS). In the rest of the article we’ll mention the WPScan tool, which […]


CrackMe Challenge Part 3: The Logic Behind the First Challenge

If we take our predicate that we’ve seen in the end of part 2 into account and input at least 64 bytes (0×40) into the Key 1 field and […]


CrackMe Challenge Part 2

The First Message Box

Let’s start our unpacked program with OllyDbg, run it, input eight A’s into the Name and Key 1 field and press CHECK STAGE 1. What happens […]


ESET Rule the Code – CrackMe Challenge Part 1: The Unpacking Process

1. Presenting the Problem

The CrackMe challenge was first observed on the ESET CrackMe web page, which looked like the the picture below:

On the web page we can observe that […]


Vulnerable Applications


How often have we found ourselves in need of a vulnerable application, which we could use for various purposes? We could use such applications to test the web application […]

Nessus 5.0.1 -  Vulnerability scanner


Nessus is an automatic vulnerability scanner that can detect most known vulnerabilities, such as misconfiguration, default passwords, unpatched services, etc.

From the following picture, we can see that Nessus can […]