What is a Firewall?The term "firewall" illustrates a system that protects a network and
machines on them from various types of attack. Firewalls are geared towards keeping server up all time and protecting entire network.
The primary goal of a firewall is to implement a desired security policy; controlling access in both directions through firewall, and to protect firewall itself from compromise. It wards off intrusion attempts, Trojans and other malicious attacks.
Personal Firewalls: They are meant for home user in a networked environment. They aim to block simple attacks, unlike enterprise level firewalls that corporate world uses at server or router end. There are many ways to implement a firewall, each with specific advantages and disadvantages.
Are they really needed? Nowadays organizations and professionals use Internet technology to establish their online presence and showcase their products and services globally. Their endeavor is to leverage digital technology to make their business work for them.
All organizations and professionals are shifting from Dialup to broadband and getting a fixed IP. It has led to an increase in security attacks, bugs in everyday working. This does not mean that Dialup being anonymous dynamic link or firewall of ISP network make you pretty safe.
Now if your machine was under attack, you must have wondered what went wrong making your system crash suddenly. So I would rather like to say, it’s not necessary for anyone to actually know about you or your IP address to gain access to your system.
If you system is infected or prone to intrusions, then beyond anonymity of your Dialup connection or a dynamic IP, your system can be hacked.
Types of Attacks
Intrusion: There are many ways to gain unauthorized access to a system. Operating system vulnerabilities, cracked or guessed passwords are some of more common. Once access is attained, intruder can send email, tamper with data, or use system privileges to attack another system.
Information Theft and Tampering: Data theft and tampering do not always require that system be compromised. There have been many bugs with FTP servers that allow attackers to download password files or upload Trojan horses.
Service Attacks: Any attack that keeps intended user from being able to use services provided by their servers is considered a denial of service attack. There are many types of denial of service attacks, and unfortunately are very difficult to defend against. "Mail bombs" are one example in which an attacker repeatedly sends large mail files in attempt at filling server’s disk filesystem thus preventing legitimate mail from being received.
Types of Attackers
Joyrider: Not all attacks on computer systems are malicious. Joyriders are just looking for fun. Your system may be broken into just because it was easy, or to use machine as a platform to attack others. It may be difficult to detect intrusion on a system that is used for this purpose. If log files are modified, and if everything appears to be working, you may never know.
Vandals: A vandal is malicious. They break in to delete files or crash computer systems either because they don't like you, or because they enjoy destroying things. If a vandal breaks into your computer, you will know about it right away. Vandals may also steal secrets and target your privacy.
“In an incident a Trojan was being used to operate web cam. All activities being done in house were being telecasted on websites.”
