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: Yes, including mobile devices.
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 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.
Q: How do I get rid of a virus?
A: Effective anti-virus programs will either quarantine or automatically delete a suspected virus payload. If a virus is quarantined, the anti-virus program will easily allow the user the delete the file.