With so many computer hackers, viruses and of course the scammers destroying the enjoyment of the Internet, consideration should be given to a computer firewall. Data that is entering your computer should be challenged by a firewall. It stops your computer being prone to dangerous attacks that can negatively impact upon you.

The firewalls available vary widely and you must determine which type is suitable for your computer. Chances are that your firewall is already set up and ready to be used if you have a computer that came installed with the Microsoft XP or Vista operating system. You must check that it is turned on and working properly. If you do not have one of these later operating systems, then you need to purchase your own software. Owners of Microsoft XP may still want to purchase separate firewall software as the XP version doesn’t get great reviews.

You can either visit a store that sells computer software or download a Computer Firewall product through the Internet - the most popular products available are Norton, AVG and McAfee. The price of software varies depending on how sophisticated it is but there are also plenty of low cost versions available, even from the big name companies. Once in hand and prior to installing your firewall, you need to take a few things into consideration. The program must be configured to permit the functions that you need, such as file and printing sharing. The information supplied gives you all the settings you need to be able to configure the software during installation or at a later date.

Firewalls can limit access to certain parts of the Internet. Awareness of how you connect is important as if you use a local area network or a router, this could happen. Accessing secured networks when you have installed a firewall is difficult. A pc linked to a company network may require a specific settings configuration to allow you to connect a firewall to them and the company’s IT department should be able to advise you with this.

Even though there seems to be allot to know when installing a computer firewall the benefits far outweigh the work required to configure the firewall to work correctly on your pc. The risk of a malicious infection or a computer intruder is far worse than having to read software documentation to have your stand alone firewall work correctly.

Reference: Firewall

Botnets are networks of computers that hackers have infected and grouped together under their control to propagate viruses, send illegal spam, and carry out attacks that cause web sites to crash.

What makes botnets exceedingly bad is the difficulty in tracing them back to their creators as well as the ever-increasing use of them in extortion schemes. How are they used in extortion schemes? Imagine someone sending you messages to either pay up or see your web site crash. This scenario is starting to replay itself over and over again.

Botnets can consist of thousands of compromised machines. With such a large network, botnets can use Distributed denial-of-service (DDoS) as a method to cause mayhem and chaos. For example a small botnet with only 500 bots can bring corporate web sites to there knees by using the combined bandwidth of all the computers to overwhelm corporate systems and thereby cause the web site to appear offline.

Jeremy Kirk, IDG News Service on January 19, 2006, quotes Kevin Hogan, senior manager for Symantec Security Response, in his article “Botnets shrinking in size, harder to trace”, Hogan says “extortion schemes have emerged backed by the muscle of botnets, and hackers are also renting the use of armadas of computers for illegal purposes through advertisements on the Web.”

One well-known technique to combat botnets is a honeypot. Honeypots help discover how attackers infiltrate systems. A Honeypot is essentially a set of resources that one intends to be compromised in order to study how the hackers break the system. Unpatched Windows 2000 or XP machines make great honeypots given the ease with which one can take over such systems.

A great site to read up on this topic more is The Honeynet Project (http://project.honeynet.org) which describes its own site’s objective as “To learn the tools, tactics and motives involved in computer and network attacks, and share the lessons learned”.

Smitfraud is one of those super annoying spyware applications. While it does not tend to do a whole lot of harm to the computer it does make working on your system that much harder. Check out this Smitfraud Removal site for more info on the actual removal process.

Smitfraud has many different variants and it will infect your system differently depending on what variant you have. In most cases your desktop will of changed to an image that you did not select. This can be something simple or a pornographic image. We have even seen a few say tons of curse words and taunt people with statements like “You have been hacked %ot&e# !@#$%^”.

As well as your desktop taken over most people who are infected with Smitfraud find their home page has been hanged, they get constant re-directs and a fake security product that gives out bogus scan alerts. Check out this Smitfraud C Removal site for more information on that particular variant.

While Smitfraud and Smitfraud C do not destroy files on your computer it is often a sign that you have other spyware and viruses installed. You should take immediate action and get these variants removed. Waiting will only worsen the problem and deepen the infection.

Regardless of what method you end up choosing you need to take action today if you are infected. If for any reason you do not have protection you should get it soon as well. Remember no free client out there offers live upfront protection. They only kick in after you get infected. Only you can take the next step and get protected.

We have all heard the term Trojan Horse, but what exactly is it? A Trojan Horse is a destructive program that masquerades as a harmless application. Unlike viruses, Trojan Horses do not replicate themselves, but they can be just as destructive. One of the most dangerous examples of a Trojan is a program that promises to rid your computer of viruses but instead introduces viruses into your computer.

The Trojan can be tricky. Who hasn’t been online and had an advertisement pop up claiming to be able to rid your computer of some nasty virus? Or, even more frightening, you receive an email that claims to be alerting you to a new virus that can threaten your computer. The sender promises to quickly eradicate, or protect, your computer from viruses if you simply download their free , attached software into your computer. You may be skeptical but the software looks legitimate and the company sounds reputable. You proceed to take them up on their offer and download the software. In doing so, you have just potentially exposed yourself to a massive headache and your computer to a laundry list of ailments.

When a Trojan is activated, numerous things can happen. Some Trojans are more annoying than malicious. Some of the less annoying Trojans may choose to change your desktop settings or add silly desktop icons. The more serious Trojans can erase or overwrite data on your computer, corrupt files, spread other malware such as viruses, spy on the user of a computer and secretly report data like browsing habits to other people, log keystrokes to steal information such as passwords and credit card numbers, phish for bank account details (which can be used for criminal activities), and even install a backdoor into your computer system so that they can come and go as they please.

To increase your odds of not encountering a Trojan, follow these guidelines:

Trojans can infect your computer through rogue websites, instant messaging, and emails with attachments. Do not download anything into your computer unless you are 100 percent sure of its sender or source. Ensure that your operating system is always up-to-date. If you are running a Microsoft Windows operating system, this is essential.

Install reliable anti-virus software. It is also important that you download any updates frequently to catch all new Trojan Horses, viruses, and worms. Be sure that the anti-virus program that you choose can also scan e-mails and files downloaded through the internet. More on Computer Security.

Well, I’ve got this article to share today. I think that many of you should know about Worm and Trojan Horse.

A computer Worm is a self-contained program (or set of programs), that is able to spread functional copies of itself or its segments to other computer systems (usually via network connections).

Note that unlike viruses, worms do not need to attach themselves to a host program. There are two types of worms–host computer worms and network worms.

Host computer worms are entirely contained in the computer they run on and use network connections only to copy themselves to other computers. Host computer worms where the original terminates itself after launching a copy on another host (so there is only one copy of the worm running somewhere on the network at any given moment), are sometimes called “rabbits.”

Network worms consist of multiple parts (called “segments”), each running on different machines (and possibly performing different actions) and using the network for several communication purposes. Propagating a segment from one machine to another is only one of those purposes. Network worms that have one main segment which coordinates the work of the other segments are sometimes called “octopuses.”

Now, Let’s learn about Trojan Horse :

A Trojan Horse is a program that does something undocumented that the programmer intended, but that some users would not approve of if they knew about it. According to some people, a virus is a particular case of a Trojan Horse, namely one which is able to spread to other programs (i.e., it turns them into Trojans too).

According to others, a virus that does not do any deliberate damage (other than merely replicating) is not a Trojan.

Finally, despite the definitions, many people use the term “Trojan” to refer only to *non-replicating* malware, so that the set of Trojans and the set of viruses are disjoint.