Viruses are flying around the Net like gnats, and keeping your PC healthy is a challenge. Check out my suggestions below to learn how to prevent infections and treat your system if it does catch a nasty bug.
Back Up Your Data
Your first step in protecting your PC from viruses--and also from any other form of system failure--is to make frequent backups of your important data on removable media (such as floppies, CD-Rs, Zip disks, LS120 SuperDisks, or some other form of writable storage). However, if you have more than a few files to back up, copying them to removable media is a chore. While most hardware comes with backup programs designed to help you make copies of your data, there are a number of applications dedicated simply to data protection and recovery. Some backup applications, like Roxio GoBack, concentrate on quick system recovery in the event of data corruption, viruses, or other hazards. GoBack takes periodic "snapshots" of critical areas of your hard drive and stores them; should something go awry, you can revert your system to its state when one of the snapshots was created. Note, however, that GoBack doesn't actually create backup copies of your files. While it's a useful recovery tool, your data still isn't safe from a catastrophic hardware failure, or a virus that completely wipes out your hard drive.
Other apps, like Norton Ghost 2002 and PowerQuest Drive Image, create images of all or parts of a hard drive, which is useful for a variety of tasks beyond simply creating backups. For instance, they make upgrading your hard drive a simple process, and in business environments they can help to quickly initialize a number of identical computers. Restoring full images is incredibly simple, and recovering individual files from images only requires you to use a simple browser-style application to select the files to be restored. The only downside of these programs is that they are geared more toward data manipulation than creating frequent, consistent backups.
The actual task of creating backups is best served by a traditional backup program such as Veritas Backup Exec Desktop Pro. This program lets you back up files from one system or from a number of PCs across a peer-to-peer network. Its scheduling applet lets you run automated, unattended backups, and its disaster recovery tools let you not only restore files, but also re-create the drive's partition and file-system information (a common target of malicious viruses) should it become corrupted. With reliable backups, your data is safe from viruses and all sorts of other dangers. That doesn't mean viruses aren't a threat, however.
Keep Your PC Healthy
The best way to recover from a virus is never to catch one. Just as you should wash your hands a lot during cold season and try to avoid sharing silverware with sick people, you should also take preventive steps to protect your PC from virus infection.
If you use e-mail, download files from the Internet, or share files with other computers, you should own a good antivirus utility. Among the finest available are Norton AntiVirus 2002, McAfee VirusScan, Panda Antivirus, and others. Better yet, many of these applications are available for download, so you can start protecting your system immediately. Symantec's Norton AntiVirus is widely considered the de facto antivirus suite, although most antivirus programs share a similar set of core features. They can scan your computer's boot areas and file systems for known viruses, check e-mail for malicious attachments as each message arrives, download updates automatically, generate emergency boot diskettes in case of a serious infection, and more.
Most antivirus makers offer different products depending on users' needs. Offerings vary from small, one-user programs for home users and very small businesses to network-monitoring powerhouses for large businesses. For the latter, virus protection should be left to the IT department or network administrator. Software licenses are a great option for businesses that need to protect a network of PCs. However, if you need more than one copy of a product, but aren't ready to purchase a license, Symantec 5- and 10-user multipacks are great options for small companies. In addition, if you're running a small network, you may want to look into a program Veritas Backup Exec Desktop Pro. As mentioned earlier, programs like Backup Exec can be used to protect personal computers; however, they are also quite effective when used to back up small networks and protect data from the hazards of hard disk failure, power surges, and human error.
Viruses and Worms
It's important to understand the different types of threats that are floating around the Internet searching for a vulnerable computer. The most widely publicized forms of Internet vandalism are computer viruses and worms. The key difference between the two is that viruses are malevolent, while worms are benign (but very annoying).
A computer virus is a program that infects part of a system, causes some sort of damage or data loss, and produces copies of itself to spread to other computers. The damage viruses cause can be minor or catastrophic, depending on the whims of their authors. Some viruses have been known to destroy the data structure of an entire hard drive or even to damage the infected computer's BIOS chip (without which a computer doesn't work at all); others simply target and destroy one type of file, such as program executables or documents.
Worms behave almost exactly the same as viruses, except that they don't damage data--they exist only to reproduce themselves and spread to other computers. It's possible to weather a worm infection without any disruption to the normal, day-to-day use of your computer. However, if a worm infects a company's network, it can set off a deluge of interoffice e-mail, which can bring down the company's computers.
Trojans and DOS Attacks
Though they're often lumped together with viruses and worms, trojans are very different. Trojans are small, innocent-looking programs that, once executed, allow intruders to assume partial or full control of an Internet-connected computer remotely, from their own PCs.
Trojans are often used in conjunction with denial-of-service (DOS) or distributed denial-of-service (DDOS) attacks, which are discussed below. In most cases, you can easily avoid a trojan infestation in the same way that you can thwart viruses or worms: by not opening suspicious e-mail attachments from both unknown and familiar parties. Trojans are often found in downloadable software from questionable sources, such as hacker sites and warez (illegally reproduced commercial software) servers.
More sophisticated than worms, viruses, and trojans are denial-of-service (DOS) attacks. These aren't programs at all, but actions undertaken by nefarious parties that result in the inability of users to perform common Internet-related functions, like downloading their e-mail or accessing a Web site. The most common form of DOS attack involves hackers triggering dozens, hundreds, or even thousands of bits of false data packets toward a particular Web site. The attack is intended to cause so much false traffic that legitimate users are unable to access the site.
Unbeknownst to you, your computer may even assist such attacks. A particularly nasty form of DOS assault, called a distributed denial-of- service (DDOS) attack, involves hackers controlling unsuspecting PCs all over the Net through the use of trojans. A hacker or group of hackers will trigger trojan-controlled computers to simultaneously send massive amounts of false data to the same target. The result is usually tons of data overloading a Web address, choking off real traffic and sometimes crashing the targeted Web server. The best way to prevent this from happening is by installing a firewall, or a program designed to block unauthorized access to and from your computer or network. See more on firewalls in the last section of this guide. Often, an antivirus program can remove viruses from files or boot areas without the need for any further recovery.
You don't have to be a victim of a virus attack, a pawn in a worm's reproductive cycle, or an unknowing assistant in a DDOS attack. By using common sense and installing protective software such as antivirus programs and firewalls, you can prevent your PC from falling victim to hackers' dubious activity.
Your first line of defense against unseemly Internet activity should be to adjust your own habits:
Don't open e-mail attachments from people you don't know--even viruses like the famous Love Bug aren't dangerous until a user activates them, usually by opening an e-mail attachment. If you receive an e-mail with an attachment from someone you do know, check the file's extension before proceeding. Image files (with extensions like .JPG, .GIF, .BMP, and such) are usually safe to open, as are text files (which have the extension .TXT). Files that may be dangerous are program executables (.EXE, .BAT, .COM, .PIF), Microsoft Word documents (.DOC), and Visual Basic scripts (.VBS). Never open a .VBS file. Delete the e-mail immediately. Regardless of the attachment's extension, save it to a folder on your hard drive and scan it with an antivirus program before you open it. When you download files and programs, scan them with your antivirus program before executing them.
What If You Get a Virus? Don't panic!
If a virus does crawl into your computer, your antivirus software will inform you of your options. Often, an antivirus program can remove viruses from files or boot areas without the need for any further recovery. You may have to boot your system with the emergency diskettes the program made for you.
Sometimes, your antivirus program won't be able to purge an infected file of its virus. The file should be deleted and replaced with a clean copy. Your antivirus software will help you through the process.
Even if you don't already have antivirus software installed when a virus infests your system, such programs can still help you rid your PC of the intruder. If your computer starts acting funky (popping up errors for no apparent reason, reporting file corruption, asking for a third cup of coffee, etc.), grab an antivirus program and give the system a thorough checkup. Programs like Norton AntiVirus 2002 and McAfee VirusScan are available for immediate download, so you can start fighting your bug as soon as it rears its ugly head.
As more and more homes contain multiple computers, it's becoming popular to network them together and share a single broadband Internet connection. Whether you're enjoying such a setup or you have single Internet-connected PC, you should consider investing in a personal firewall.
Firewalls block unauthorized access to and from your computer or network. Information is transferred to and from your PC via open ports, which are basically data conduits. Firewalls block vulnerable ports that can be used by hackers to control your system with trojans or perform other malicious tasks. As such, firewalls are especially useful in preventing your computer from taking part in a DDOS attack, or from being accessed by hackers even if you've already unknowingly installed a trojan.
Among the best and user-friendliest firewalls available are Norton Personal Firewall and McAfee Firewall. If you don't have any Internet security programs yet, check out Norton Internet Security--it's an outstanding buy that includes a firewall, an antivirus program, and more.