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Does your Computer have a virus? are you sure? Click here for our recommended free virus scanner.

Your data is the most important thing on your computer and it is important that you know how to take care of it. The first, and safest, thing to do is back up all your important data to external devices. If you have copies of your personal and important files saved either to a floppy or compact disk or USB stick, you will be prepared for even the worst case scenario. For example, if your entire system is ravaged by a virus requiring you to reformat your hard disk and wipe everything, you will have copies of all your data to reinstall.

A computer virus is a program that is developed to spread from file to file, much like a biological virus, self-replicating and taking over the computer piece by piece. Once a virus has accessed your computer it will multiply and attach itself to more and more files and folders. If files are infected by a virus, they can become corrupted as the virus code multiplies and eventually overpowers the original files.

Even if you don’t have backup copies saved and files become corrupted as a result of a virus, application errors and system crashes, there are ways to recover your data.

If you discover a virus on your computer at an early enough stage, then it can likely be removed by antivirus software. A data recovery program would likely be able to restore your files if the damage is minimal. If a virus or other malware has damaged your files, or if your system has unexpectedly crashed and deleted unsaved files, software programs on the market are available for restoring your lost data such as ParetoLogic Data Recovery.

One way to retrieve your files is to try to restore it from the most recent back up. For example, Microsoft Word makes back up files with a .wbk extension and saves it in the same folder. To open it, rename it with a .doc extension.

Another thing to try is to run System Restore, which recalls system files (not document files) in the form that they were in at an earlier time. While this process can work to recover files, it is important to run your virus scan again as viruses can be re-installed by System Restore even after the rest of the system was cleaned.

If the virus is left undetected for too long, it can do lasting and irreparable damage to your computer. If the virus spreads and a lot of damage is done, you will notice serious problems like frequent error messages, programs quitting unexpectedly and, eventually your computer won’t boot up at all.

If this happens, then sometimes the only way to save your system is to sacrifice your saved data and format your hard disk in order to salvage your hardware. There is a chance that data can be restored even after your hard disk has been formatted, with a good data recovery program or with the assistance of a technical specialist.

Does your Computer have a virus? are you sure? Click here for our recommended free virus scanner.

There are several ways that a computer virus or other form of malicious code can infect your computer. Depending on the type of malicious code that has penetrated your system, it is possible to determine the most likely source of your problems as well as ways to protect your system against threats in the future.

The term ‘virus’ has come to be used popularly to describe all kinds of malicious software that can infect your system, but it is useful to understand the different intentions and causes of different varieties.

Viruses are programmed to behave like a biological virus and spread from file to file inside an infected computer, self-replicating until the infectious code is more expansive than the files that they infected. As the virus spreads, the system will encounter numerous problems including: slow functioning, error messages, an inability to run programs and, eventually, an inability to run the operating system or even boot up.

If your computer has been infected with a virus, there are a few likely sources to consider. Viruses require a host file to spread from one system to another so, if you have recently opened a file from another source, you may have inadvertently allowed the virus access to you system. Infected files are spread a number of ways: by external devices like USB ports or floppy disks (if an infected file is saved on a device from an infected system and opened on another, the virus is spread), opening unknown attachments, and downloading infected programs.

Worms are another form commonly used to package malicious code. Worms are similar to viruses in that they are self-replicating and will spread themselves but, unlike a virus, worms do not require a host virus, nor are they primarily interested in a single computer. Worms are designed to penetrate computer networks and provide their designers with remote access to systems as well as the information they contain.

Worms are spread in the same way as viruses, through software from the Internet or by email. Since worms don’t require a host file they can spread without the user even opening or executing an infected file. For example, if you follow an unknown link on the Internet it can open a website that is pre-programmed to upload the worm automatically.

Trojans are another common form of malware. Unlike both viruses and worms, Trojans don’t self-replicate and their goal isn’t usually to take over the computer, more often it is to establish a ‘back door’ through which the hacker can gain access to the computer.

Trojans are spread in disguise, like the original Trojan horse that the Greeks used to infiltrate the city of Troy. The Trojan is disguised in benign-looking software (like antivirus scanners) so that when the software is downloaded, the Trojan gains access to the system.

As well, Adware (advertising software) and spyware (software designed to spy on the user) are also spread by opening infected files or following bad links on the Internet.

Click here for our recommended free virus scanner!

The first possible line of defense for your computer system is a router. Usually used to network computers or share modem access between computers, a router acts as a hardware firewall between the computer and external sources.

One way that hackers gain remote access of computers is by infiltrating IP addresses and finding accessible ports. A router stands between the computer and the external threat making the IP address difficult to read and interfering with port scans. Often the complication of getting past the router is enough to make the hacker look for an easier target.

There are also firewall software programs that act as security guards against anything or anyone that tries to access your computer. Firewalls are often built in to operating systems like Windows or OSX and can be set to the users specifications. The highest level of defense is to let nothing access the system, but that might not be realistic if you use your computer for peer to peer sharing or other functions that involve up and downloading data. Firewall software can be set to allow traffic from known and pre-approved sites as well as to notify the user with a pop-up message and request permission to allow access each time the system is contacted.

A very important step towards protecting your computer and stored data against threats is to install and maintain an up to date antivirus program. Unlike the earliest models that were specifically written to combat viruses, modern programs are adept at identifying, isolating and/or deleting infected or suspicious program code or files.

Antivirus software is an important component of your computer security and should be kept at optimal performance with constant updates. However, even then there are limits to what it can do. Since the program can only detect viruses that are included in its dictionary your computer is always vulnerable to new viruses.

Another way that virus writers keep ahead of antivirus software is by writing code that is partially encrypted and disguised so as to not register with the dictionary. As hackers and virus writers get more sophisticated, so do the antivirus programs that combat them.

A simple but effective way to keep your system secure and clean is to be very careful about downloading files from the Internet or opening files that you receive by email.

Infectious files may look harmless but actually carry dangerous code. For example Trojans are often packaged inside programs claiming to be antivirus software that contaminate the computer and facilitate remote access of your system to the hacker once they are downloaded.

While it may be common knowledge that you shouldn’t open attachments that you receive from unknown email senders, even those that come from your contacts can not be fully trusted. Viruses and other malware programs can hijack email accounts and use the address books associated with them to mass-distribute infected files. If you receive unexpected attachments from your contacts, or suspicious emails, it is safer to check with the sender before opening any potentially dangerous files.

As well as these security features, it is important to use common sense when using your computer and when accessing sites on the Internet. Always use strong passwords that cannot easily be discovered by an intruder. Avoid using important dates or personal information like addresses as passwords because this information may be accessible to someone that has infiltrated your computer.

Lastly, make back-up copies of important data. Irreplaceable media and text files should be saved to CD and stored externally in case of infection and data loss. In this case, at the very least, should your system be attacked and infected you will have copies of your important information and data.

Click here to scan your computer for viruses

Virus scans are so named because at the time they were developed computer viruses were the biggest threat to personal computers and so the protective software was designed exclusively for viruses.

These days antivirus software looks for and eliminates many kinds of suspicious or malicious code that might have infiltrated and infected you computer. Malicious programs include viruses, Trojans, worms, adware - that installs pop-up ads - and spyware - that tracks your browsing habits and records the website you use.

Whereas viruses are designed to multiply, infect and destroy files other threats like worms and Trojans can creep in the background of the computer system and open ports for external remote control, access personal information and route spam through the IP address. In order to address the different modes of operation of different malware antivirus programs use two different approaches.

First the program scans the files and compares them against a list of known viruses. Antivirus programs use a virus dictionary and compare code on the computer against the list of known viruses. If any infectious code is found the program can first attempt to repair the file by eradicating the virus itself. If it is unsuccessful the antivirus can quarantine the file, isolating it so that it cannot spread to other files and will then prompt the user and ask what to do. Some antivirus software programs will delete the infected files without waiting for the command so it is important that you understand the specifications of the program you install.

It is possible that a virus can contaminate data files stored on your system and corrupt or infect them. If the virus scan detects and deletes the file you can lose data. For this reason it is a good idea to save back up copies of all your important or personal information on a removable device like a USB stick or a disk.

Once you have installed antivirus software on your computer you can set the specifications to run automatically at set intervals as well as run manual scans periodically or when you download new files from outside sources.

Virus and other malware writers are constantly coming up with new and more sophisticated code. In order to stay up to date it is important to check the software vendor’s website often for updates.

As well as looking for code that matches its dictionary definitions, virus scans also check the computer’s performance, looking for any suspicious or unusual behaviour. If you run Windows operating system you can check yourself to see what programs are running on your computer and what programs are launching automatically when you boot up your computer. Viruses and malware often infiltrate these locations, running code and initiating applications without the user’s permission or knowledge. To check what programs are running in the Control Panel, in Administrative Tools, Services you can see a list of the programs that your system is running. To check your auto-launch list go to the Start Menu, Run and type misconfig.

Antivirus software is really important if you use your computer to browse on the Internet, download files and/or email attachments and other software programs.

The function of a firewall is to monitor and control communication and data exchange between your computer and external people, programs, or systems.

Even if you only have one computer and do not need it for networking purposes, a router is the most effective hardware firewall. A router stands between your computer and the outside world as your first line of defense and interferes with attempts to read your IP address or perform port scans on your system. When a hacker tries to access your computer they are looking to access to your bandwidth or your IP address. The router is able to block or considerably slow the hacker’s ability to access the information. Since many computers are not protected by hardware firewalls most hackers will opt for an easier route and move on to another target.

In addition to hardware router devices there are also a number of software applications designed to protect your system. There are a number of commercial firewall software programs available for free download, but some of these programs, while effective for firewall protection, are not equipped with anti-virus protection like the retail versions of the same products. If you do not already have a comprehensive security program installed on your computer it is advisable to purchase a complete system. Also, somewhat ironically, some malicious software, most often Trojans, are packaged inside software programs that are advertised as free antivirus softwar

If you decide to install a personal software program it is important that you first remove any other firewall programs using the software uninstall or Windows add/remove tool in the control panel. Also, before installing a new software program be sure to turn off the operating system firewall if there is one. Once installed it is important to check the website of the software program to check for updates and patches to ensure that your system and its software are kept up to date.

Operating systems like Microsoft XP, Vista and Mac OSX are equipped with built-in firewall technology that is automatically operative. These systems generally advise the user to leave the firewall activated unless they require increased access to and from the Internet. It is possible to adjust the preferences to allow exchanges from pre-authorized sites or to notify the user on a case by case basic with pop-up windows alerts.

In order to check the new firewall and confirm that your system is protected there is also port scanner software that will scan your system or network for any available ports. If the firewall is operative none will be found or you will be somehow notified about a potential breech.

Since the purpose of a firewall is to protect your computer from external interference and potentially malicious software by restricting any exchange of data files, if you want to use peer-to-peer sharing websites or up and download files regularly, you will have to set some specifications. Firewalls can be set to allow traffic to and from pre-approved sites or to prompt the user for permission before allowing a program access to the computer.

Click here for our recommended free virus, trojan and worm scanner.

The term ‘virus’ has come to stand in for any dangerous or destructive computer programs but is technically only one of three main types of malicious software, or malware that can penetrate and damage your computer system and/or perform unwanted or unauthorized functions.

Each form of malware is essentially a software program designed to run specific applications on a computer. Some are programmed to damage or delete files, others to take over bandwidth and allow third party access to personal information or to send and receive information via the victim’s IP address.

All viruses are code written to perform or fulfill a specific task. Some are merely annoying and might do no more than put a silly message on your screen. Others are destructive and programmed to delete information or destroy the hard disk.

Viruses are mainly spread through emails and are launched when the receiver unknowingly executes the program by opening the attached file. Viruses are predominantly designed to attack and spread throughout the computers on which they have been executed, spreading from file to file throughout the computer, rendering programs delayed or inaccessible.

The virus works by placing itself in the computer’s memory then attaching itself to any programs that are executed. Once infected, every time the program runs the infected file will duplicate itself. Over time a virus that began as very small becomes larger and larger until eventually it is bigger than the original files and the programs are no longer able to run.

Trojans are primordially used to penetrate computers and establish back doors through which hackers can remotely control the system, access personal information and hijack the IP address. Unlike viruses and worms Trojans are not self-replicating and instead run in the background of the computer, avoiding detection and acting as inside guys for the hacker. Once a hacker has gained remote access of the system they can then issue commands, retrieve sensitive and personal information and route illegal data through the victim’s IP address to shield themselves and their actual location from detection.

Worms are similar to viruses in that they are self-replicating and do not require a specific file to spread. Worms reside in active memory and are programmed to spread themselves through networks gaining access to multiple ports and IP addresses rather than infect and immobilize a single host computer. Like Trojans, worms are used to penetrate computers, most often computer networks and establish back doors to provide remote access of networks of computer including the use of bandwidth that will interfere with and slow the functioning of the computer and the network as well as IP addresses that are useful to spammers and credit thieves.

There are many ways to protect your computer or computer network from malicious software. First, install a router or a software firewall to monitor data exchanged over the Internet. Install up to date antivirus software and frequently check for updates to known virus definitions and be vigilant in checking the source and content of data files before downloading and/or opening attachments.