Q: What is a virus?
A: A virus is a piece of malevolent programming code that when executed will infect files and corrupt them. Worms and Trojan Horses are also malicious programs that are often referred to as viruses, but are different than viruses in some respects. Understanding the difference between them will help you better protect against blended threats.
- A computer virus attaches itself to a program or file so it can spread from one computer to another. Since viruses attach themselves to executable files, they cannot infect your computer unless you run/open the malicious program. Human interaction is required to spread a virus, for example opening an infected email attachment or running an infected program downloaded from the internet.
- Worms are similar to viruses except they have the ability to travel without human intervention. Worms replicate themselves and spread by, for example, emailing everyone in your address book. The worm continues to replicate and then sends itself out to everyone listed in each of the receiver's address books, wreaking havoc on network systems by consuming memory and bandwidth to a point where web servers, network servers, and individual workstations stop responding.
- A Trojan Horse masquerades as a useful, legitimate program that once installed can create a "back door" for hackers to gain access to computer systems so they can steal personal/confidential information.
Viruses, Worms, and Trojan Horses are often accompanied by other security risks and are referred to as "blended threats" that can include, but are not limited to: spyware, adware, keyloggers, drive-by downloads, popups/popunders, phishing, pharming, spam, dialers, homepage hijackers, search engine redirectors, and the list goes on….
Q: Are all computers at risk?
A: Mobile devices are vulnerable to viruses written specifically for them, but these threats are not nearly as common as those designed for Windows PCs. Macintosh computers are also susceptible to viruses but the majority of viruses target Microsoft's Windows Operating Systems.
Q: Who writes viruses and why?
A: Virus code is written by programmers and can be the result of poorly written code or a programming mistake, but is more often based on intentional vandalism, making political statements, or the desire to reap financial benefit through identity theft.
Q: What are the symptoms of a virus?
A: Symptoms include:
- system restarts or crashes
- computer won't boot
- slow performance
- loss of internet connectivity
- email in your SENT mailbox that you didn't author
- error messages about missing or corrupt system files
Q: What happens if my computer gets a virus?
A: Virus payloads can vary from the installation of annoying joke programs to data destruction or preventing your computing from starting. Most viruses can be quarantined or removed using anti-virus software, but many have special removal instructions (registry edits, remove from SafeMode, disable System Restore in WinXP) that if not followed will result in re-infection. If you are unable to completely remove a virus, reformatting the hard disk and reloading the operating system may become necessary.
Q: Will my computer detect a computer virus?
A: If you have anti-virus software installed and the virus definitions are up to date, the software should quarantine any threats before they compromise your system.
Lafayette provides anti-virus software free of charge for all students and employees (including home computers) from Symantec
Be sure to read the installation notes and set up instructions before installing the software! Improper installation of anti-virus software can be harmful to your system.
Q: How do I get rid of a virus?
A: Symantec detects and quarantines virus-infected files. If you don't have Symantec installed or a virus has disabled your anti-virus software, an assortment of free removal tools are available:
- McAfee's Stinger Download
- Symantec Removal Tools
- F-Secure Removal Tools
- Microsoft Malicious Software Removal Tool
Note: Lafayette College does not endorse, encourage the use of, or provide support for these tools, nor can it accept any liability arising from their use. Links are provided for your convenience only.
Q: Can I protect my computer from getting a virus?
A: Prevention is key and the following are examples of best practices: