This Tech Tip will provide you with some education around Computer viruses, What is a Computer Virus and the many different types of computer viruses. We will also provide some tips and tools to protect your computer and recommendations around safe computing. Information provided in this hot tip can not only be used within the workplace but also for home computing.
What is a Computer Virus?
A computer “Virus” is an umbrella term used to describe malicious programs that unwantedly install themselves onto your computer. Viruses will cause you a range of damage, from the very mild to the entire loss of your computer data. Another word commonly used in relation to viruses is “malware”, or software programs that have malicious intent. Given that the word Virus is commonly used in the medical world, the word Malware is the more preferred word to use in the computer world.
Viruses/malware are commonly broken down into – Viruses, Trojans, Worms, Adware and Spyware.
Viruses are malicious programs that rewrite existing computer code on your computer. Classic viruses are not so much unwanted additions to your system as they are mutations of existing code that when executed can damage files and data.
Trojans, or Trojan Horses
Trojans, or Trojan Horses are additions to your system. These malicious programs masquerade as legitimate files in your email, deceiving you into wilfully adding them to your hard drive. Trojans rely on you to intentionally open your computer to them. Once on your machine, Trojans then function as independent programs that operate secretly. Commonly, Trojans steal passwords or perform “denial of service” (overload your system) attacks.
Worms, or Internet Worms
Worms, or Internet Worms, are also unwanted additions to your system. They are different from Trojans, though, because they copy themselves without your direct assistance… they robotically worm their way into your email, and begin broadcasting copies of themselves without permission. Because they do not require user intervention to reproduce, worms reproduce at an alarming rate.
Adware and Spyware
Adware and Spyware are cousins to trojans, worms, and viruses. They are designed to observe your Internet habits and then pummel you with advertising, or to report back to their owners via secret messages. Sometimes, these products will even use your hard drive to store and broadcast pornography and advertising back to the Internet. Nasty!
Viruses and similar malicious programs usually spread in one of several ways: from external media such as CDs and USB flash drives, from vulnerabilities in Windows programs, from downloads off the Internet or bulletin boards, from browsing infected Internet sites, from using Instant Messaging, and from email attachments.
Do’s to Avoid Viruses
Prevention is a matter of awareness and vigilance, using appropriate tools to protect your computer, and avoiding contact with unknown disks. It is usually the unwary who get computer viruses. Bleow is a list of some recommendations for safe computing:
- Keep your operating system current with the latest patches and updates. The writers of viruses and worms often exploit bugs and security holes in operating systems and other computer software. Software manufacturers frequently release patches for such holes.
- Install antivirus (virus detection) software. Antivirus programs perform two general functions: They scan for and quarantine or remove viruses in files on disks, and monitor the operation of your computer for virus-like activity. Most antivirus packages contain routines that can perform each kind of task.
- Keep your virus detection software updated. No matter which antivirus software package you choose, it is important to update it on a regular basis. Viruses are constantly evolving and new ones are always being created, so an out-of-date antivirus program may not detect or protect against the most recent variants. The developers of any reputable antivirus program will issue updates on a regular basis, usually at least once a week. There will always be an option to automatically update when updates are available to save you manually updating
- Handle attachments wisely. If you do not know the sender of a message and it includes an attachment, proceed very cautiously! You may want to consider deleting the message without reading it. E-mail attachments are quite often the culprits in many virus attacks. Therefore, if you do decide to open an attachment, be sure that it has been scanned with antivirus software. Never open attachments unless you have verified that they are free of known viruses.
- Train everyone who uses your computer or network. At a minimum, family members and employees should know not to open unexpected attachments and not to execute software they download from the Internet until they have scanned it for viruses.
- Back up your files regularly. Viruses are one more very good reason to always back up your files. If you back up a file that is already infected with a virus, you can reinfect your system by restoring files from the backup copies. Scan your backup files with virus scanning software before using them.
- Keep your original application and system disks locked (or write-protected). This will prevent the virus from spreading to your original disks. If you must insert one of your application disks into an unknown computer, lock (write-protect) it first, and unlock your application disk only after verifying that the machine is virus-free.
- Obtain public-domain software from reputable sources. Check newly downloaded software thoroughly using reputable virus detection software.
- Quarantine infected systems. If you discover that a system is infected with a virus, immediately isolate it from other systems by unplugging or disconnecting it from the network. Do not allow anyone to move or copy files from it to another system until the system has been disinfected.
- Use caution when using the Preview Pane in Microsoft Outlook. When the Preview Pane is enabled, there is greater opportunity for a virus to come in through an email.
Don’ts to Avoid Viruses
The following activities are among the most common ways of getting computer viruses. Minimizing the frequency of these activities will reduce your risk of getting a computer virus.
- Don’t freely share computer programs and system disks, or download files and software through file-sharing applications such as LimeWire or BitTorrent.
- Never download executable software from public-access bulletin boards or Web sites.
- Avoid using your personal disk space (e.g., USB drives) with public computers or other computers that are used by more than one person, unless you know they are adequately protected.
- Don’t open a suspicious attachment without scanning it first with an updated antivirus software program. scanning an attachment to your computer does not automatically remove any virus that may be present.
- Don’t open any email attachment that ends in .exe, .ps1, .vbs, or .lnk on a computer running Microsoft Windows.