Section II: What is Malicious Code?

Malicious Code or Malware is attack software and includes such things as Viruses, Worms, Trojans, Spyware, Bots, and Adware.

Each attack software has specific characteristics and propagation techniques. Some are worse than others. When it comes to malware, remember bad things can happen to good people. This section will attempt to provide you with information that you can use to protect your cyber world not only at work but also at home.

What is a Virus?

A virus is a small malicious program designed to infect files or operating systems. It is spread across the Internet, from one computer to another. For example, a camera plugged into a USB port on an infected computer can become a "carrier" and move the virus to the next computer it is plugged into.

A virus can spread without your knowledge. It needs a host or "living" program to survive. Viruses can

• Destroy operating systems
• Make backup copies of itself
• Delete or corrupt files
• Disable anti-virus software
• Send e-mail to contacts listed in your address book or steal your contacts list

Viruses spread by

• Removable media such as USB sticks, memory cards, cameras, or any media that can be inserted into your computer.
• E-mail attachments such as pdf, Word, Excel, or .exe files. Be wary of unexpected documents attached to seemingly legitimate email. Better to call the person and ask before opening.
• Internet downloads especially game or porn sites (illegal as a work activity!). Email invitations to click from unknown persons should probably be deleted!
• Keeping autorun enabled on your PC. Though it is slightly inconvenient you can reduce the risk of the virus spreading via media by disabling autorun.

If all this sounds like the typical flu season warnings then you know why the name "virus" is used. Carrying this analogy a bit further: we protect ourselves from becoming infected with the flu with the annual flu shot, by washing our hands frequently, and avoiding crowded places where the infection may exist and easily spread. Think of anti-virus software as the "flu shot". Keeping your anti-virus signatures up-to-date as well as applying vendor patches when they are available is akin to the frequent handwashing. Refraining from indiscriminate clicking on email attachments, websites, or pop-ups can be compared to avoiding crowded places. Unfortunately, unlike the "flu season" that usually lasts for a limited time, computer viruses are always "in season"!

Defense against viruses: keep anti-virus signatures up-to-date and patch often.