FAQ What is a Computer Virus? Are Some Viruses Hoaxes? Does !000 or other "e-mail fixes" really work? What Kind of Files can Spread a Virus? How do Viruses Spread? What do Viruses do to Computers? What are the Symptoms of Virus Infection? How can I Avoid Virus Infections? Are pictures safe? What can You do to Protect Against Viruses? Are there free virus protection programs? What is the "best" anti-virus software on the market? What might be the Most Important Thing I Can Do? Virus Pattern Scan Engine Hackers, Crackers, and Virus Writers My anti virus protection came from a bundled program. That's all I need, right? My internet service provider (ISP) will protect me from viruses, right? Is there a site that will compare security sites and products?   What is a Computer Virus? A computer virus is a program that has the ability to make copies of itself, and spread to other files. Viruses can attach themselves to many types of files and programs, and spread as files that are copied and sent from one computer to another. Just like biological viruses, computer viruses spread quickly and can be difficult to disinfect. All viruses are created deliberately, they are not accidents or just pranks, but malicious. In addition to copying itself, many computer viruses deliver a "payload." While some virus payloads merely display messages or images, others can destroy files, reformat your hard drive, or send unintended email messages. Even if a virus doesn't contain a damage routine, it can still cause trouble by wasting storage space and memory. Some viruses are poorly written, and may cause a computer to stop or damage files. Many viruses make the computer's memory unstable or cause programs to run improperly. More than 30,000 have been identified and hundreds of new ones are created almost weekly. Are Some Viruses Hoaxes? Often there are messages passed around by e-mail "warning" of impending viruses that are being passed. Sometimes the internet community does a good job of warning about such things. More often than not, these are hoaxes and bogus reports. One web site does a great job in keeping up with these hoaxes. It is called Vmyths.com, short for Virus Myths. Of course, it is always good to check with your virus software web page or the alt.comp.virus newsgroup to be up to date. Does !000 or other 'email fixes' really work?" In a word, NO! Nothing takes the place of a good virus program that is KEPT UP TO DATE. Click here for more info on this "hoax." What Kind of Files Can Spread a Virus? Viruses can infect any type of file that contains executable code. Originally, these were just "program files" which were, and still are, directly executed by the computer such as files with .COM or .EXE extensions in Windows/DOS. Today, many other file types can contain executable code such as word processing and spreadsheet documents that use macros, which are simple embedded programs.  Other viruses infect executable code in the boot sector of floppy disks or in system areas of hard drives. And it's possible for HTML documents to spread viruses or carry other forms of malicious code through JavaScript or other similar types of script. Since virus code must be executed, files that are recognized by the computer as pure data files are generally safe. These include graphics and sound files such as .gif, .jpg, .mp3, or .wav files as well as plain text in .txt files. Just opening a text file or viewing picture files won't infect your computer with a virus. The virus code has to be in a form that the computer will actually try to execute. How do Viruses Spread? Many years ago, most viruses spread mainly through floppy disks. Infection happened when users swapped files or borrowed diskettes from friends, school, or work. Among PCs on a network, viruses can spread very quickly when users share an infected file. More recently, the Internet has introduced new and more efficient ways to distribute viruses. With the ubiquity of email in both businesses and homes, viruses are spreading faster than ever. Viruses attached to email messages can infect an entire network in a matter of minutes, costing companies millions of dollars in damaged data, lost productivity, and clean-up expenses. What do Viruses do to Computers? Viruses run on your computer just like software programs. Their actions depend on the programming written by the virus writer. Some viruses are deliberately designed to cause damage by deleting certain types of files, or even reformatting a hard drive and destroying all data. Others interfere with your computer's operations in various ways. Many viruses only spread themselves, but these are still harmful, since they may damage files or cause problems in the process of spreading. Viruses also take up space in your computer's memory and reduce its performance. Viruses, however, can not damage hardware hardware like your hard drive. It can damage your BIOS (input/output) system. They won't burn out your CPU or cause a meltdown in your hard drive. Warnings about viruses that will physically destroy your computer are hoaxes, not legitimate virus warnings. What are the Symptoms of Virus Infection? They vary widely. Some viruses announce themselves openly; displaying a message, flashing graphics, or even playing music. Others cause severe damage or carry out other actions that quickly attract attention such as sending out a large number of email messages. However, some viruses are designed to remain hidden. In certain cases, these viruses cause strange things to happen to a computer - like a slowdown in operations, decrease in memory, or a disk drive LED lighting up for no apparent reason. You should also watch for files that change in size or disappear.  However, legitimate software programs or hardware glitches can also cause many of these effects, so don't immediately jump to the conclusion that your computer is infected just because unusual things happen. How Can I Avoid Virus Infections? Install antivirus software from a well-known, reputable company such as Trend Micro's PC-cillin 2000. Use it as recommended and be sure to update it regularly! PC-cillin will remind you of the need to update; it will even perform the update for you -- if you let it. New viruses come out every day, so if your software is out of date it may not protect you. Scan all new programs or files that may contain executable code before you open or run them, no matter where they come from. Although rare, there have been cases where retail software floppy disks and CD-ROMs sold in stores have spread viruses. If you receive a message with an attached file from an unknown source, simply delete it. If you receive an attached file from a friend or acquaintance unexpectedly, verify that it is genuine before opening it. Remember, the Melissa and ILOVEYOU viruses mailed themselves to addresses in the user's address book, so they often appeared to come from friends or associates. Be extremely careful about downloading files and documents from unknown or "dubious" sources such as newsgroups or Web/ftp sites that you do not know well. Never open executable files unexpectedly received as either attachments in email messages or during an online chat session. Maintain high security settings on your operating system and Internet applications. For example, if your email program automatically executes JavaScript or if Word does not warn you about macros embedded in documents that you open, you should increase your program's security level. Perform regular backups in case a virus or trojan erases or corrupts files on your hard drive. This will also protect you from disk failure. In either of these cases, a recent backup may be the only way to recover lost data. If you cannot backup your entire system, at least backup files that you can't afford to lose or that would be difficult to replace like: documents, bookmark files, address books and important E-mail etc. Are pictures safe? Usually, pictures are safe from virus but even that's not always true. Somes malicious code is passed around with a file extension of .shs or .shb (which are scrap files) which Windows doesn't show. If you have a file which appears as something.jpg in Windows Explorer but the actual file name is something.jpg.shs which is executeable and will probably be malicious. One safe way to check out new files of this kind is to Open them in your picture image viewer application whatever it may be. If they display normally as pictures,they're probably ok. What can you do to Protect Against Viruses? There are many things you can do to protect against viruses. At the top of the list is using a powerful antivirus product such as Trend Micro's PC-cillin 2000 for home users. (this is one of many programs but a very good one) Corporate users can learn how viruses infiltrate their networks by viewing our interactive "Trend Enterprise Solution" diagram. For further suggestions see the International Computer Security Association's Web site. (There are many sites like this which you can find on the "Tools and Links" page.) What might be the Most Important way to Protect Yourself? Update, Update, Update. If you have an anti-virus programs, don't be lulled into a false sense of security by thinking it will work without updates. Most companies extend update privileges and you should do it weekly! That is the only way you can be sure you have the most recent protection against the newest viruses. Virus Pattern A "virus pattern" (also known as a "virus signature"), is the digital fingerprint that identifies a file as being infected with a computer virus. When an antivirus company receives a new virus, they take a binary pattern of the file and add it to a database called the virus pattern file. During scanning, the binary code inside the virus pattern file is compared to the code of the files on your computer, and if there is a match, the file is deemed to be infected with a virus. All input to a computer is converted into binary numbers, made up of the digits "0" and "1." When programs tell a computer what to do, the instructions are in machine language, expressed in binary code.  How is a Virus Pattern Created? A virus pattern is a short piece of binary code that is used to identify a virus-infected file. These are generated according to the specific file format and means of virus infection. When any Windows file is infected, we carefully follow the process that Windows uses to handle this file type until we locate the virus' entry point. Once its "hidden" place is discovered, a virus pattern for the scanning program will be generated from this part of the file. Antivirus companies like Trend Micro have teams of specialized antivirus engineers who collect the virus patterns of all newly detected viruses. However, with the number of viruses growing so rapidly, finding every unique virus pattern becomes a difficult job. An incomplete virus pattern could incorrectly identify normal, i.e., non-infected, files as being virus-infected. When a new virus pattern is isolated, it is rigorously tested by scanning many types of files to ensure that it does not cause false alarms. Only after the testing is successful will the virus pattern be complete. Scan Engine The scan engine is the heart of any antivirus software, and the true measure of its quality. It is the part of the program that scans your files and detects viruses. No matter how attractive an antivirus program's user interface, its ease of use, or its function set, it is the scan engine that determines how good the software is at catching viruses. When an antivirus program scans a disk drive or directory, it sends the files one-by-one to the scan engine for comparison with the virus pattern file. A superior scan engine will perform this check quickly, while using relatively little system resources. Hackers, Crackers, and Virus Writers Virus writers may or may not be hackers, but very few hackers are virus writers. Some members of both groups may be crackers, but most of them aren't. Here's a definition of the terminology: Hackers A slang term for a computer enthusiast. According to the Jargon File compiled by long-time hacker and open source guru Eric Raymond, a hacker "is a person who enjoys exploring the details of programmable systems and how to stretch their capabilities, as opposed to most users, who prefer to learn only the minimum necessary." Among professional programmers, the term hacker implies an amateur or a programmer who lacks formal training. Depending on how it is used, the term can be either complimentary or derogatory, although it is developing an increasingly derogatory connotation. The pejorative sense of hacker is becoming more common because the mass media uses the term to refer to individuals who gain unauthorized access to computer systems for the purpose of stealing and corrupting data. Hackers, themselves, maintain that the proper term for such individuals is cracker. It should be noted that many people who call themselves hackers have a strong interest in network security. "Ethical hackers" break into networks to test their skills. Often they'll hack in, poke around a bit, and leave without causing damage. Crackers Crackers, on the other hand, break into networks to deface Web pages, corrupt data, and similar acts of vandalism. Hackers hate crackers, even though the public tends to lump them together. Virus Writers Finally, there are virus writers. Instead of using network technology to gain access and information, they focus on writing programs that can replicate and spread throughout a single network or across the Internet. They usually transmit viruses through email or Web downloads. Bundled Anti Virus Programs Anti virus software that comes bundled with your computer will only protect to the date that it was loaded onto your computer. That means it is current to BEFORE you received your computer. You will need to subscribe and update whatever that software may be. You can do this online and THEN, you can set it to automatically remind you to update. It will not do it on its own. Better yet, why not pick a day and always update then. At least you'll be doing it on a weekly basis then. ISP Protection? Your isp "might" have some anti-virus software in place but don't trust that. Take the responsibility to keep track of this on your own. Buy and update your own protection. A great site that combines most security concerns, products and comparisons can be found by here clicking here. (these FAQ's can be found at Trend-Micro's antivirus web page. Trend-Micro is a leader in anti-virus software.)