c1-cracking abex's 5th crackme : Reverse Engineering

Cracking abex's 5th crackme : Reverse Engineering

Step into firewall

Most people focus about antivirus software. But they do not have that much idea about firewalls.

According to the Wikipedia

Firewall is a network security system that monitors and controls the incoming and outgoing network traffic based on predetermined security rules.

Whatever the Wikipedia says we will look what that is useful for us.

You don’t want to be computer genius to handle basic firewall configurations. This is not an antivirus software.

Why do we use Firewall

1. Can stop malicious software try to connect to internet.

Let’s say there is a Trojan horse that send your pictures to someone else. We can stop this.


2. Can monitor what are the software that currently connected to internet and how much data it is using.


3. Can stop background updates.

If you have a media player that try to update every day we can stop that. Updating and getting new features are cool but we can stop if it does too much.

Protect from virus // Before attack

Protecting computer before the virus attack is the most intelligent move. Most people just stay and they will panic if there is a virus and there will be less chance of recover. We can minimise the damage and less recover time if we follow precautions.

We are going to eat an apple day by day to keep doctor away.

Important places and paths

Startup Locations

Registry paths (go to Run (Windows+R) and type regedit)

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run



// HKEY_CURRENT_USER path is use for startup programs work in current user.
// HKEY_LOCAL_MACHINE path is use for startup programs work entire computer.

Startup folder


C:\WINDOWS\Start Menu\Programs\StartUp



// Whatever program , shortcut or file in this folder will launch with computer startup.