Worms, Viruses and Other Internet Critters

Over the past few months, there has been an increase in the number of attacks on our network and computers coming through email. There seems to be no end to this problem anywhere in the near future. The people creating these worms/viruses will continue to create havoc until there is a technical means of identifying them and holding them accountable for their deeds. So what can be done until that time?

A few facts first...

• There are over 81,000 known viruses/worms as of February 27, 2004.
• In 1999 alone, $7.6 billion in damage was done by viruses.
• The main method of virus/worm delivery today is via email with an attachment.
• Computers using the Microsoft Windows operating system (95, 98, Me, NT, and XP) are the most favored targets of virus/worm writers.
• There are very few virus/worms written for Macintosh and Linux operating systems, though they do exist.
• Popups that plague web pages are not a virus, rather they are known as "spyware" and while anoying are not causing damage to your computer or the network.

A few definitions...

• Virus: A computer program file capable of attaching to disks or other files and replicating itself repeatedly, typically without user knowledge or permission. Some viruses attach to files so when the infected file executes, the virus also executes. Other viruses sit in a computer's memory and infect files as the computer opens, modifies or creates the files. Some viruses display symptoms, while some viruses damage files and computer systems.
  
• Worm: Worms are parasitic computer programs that replicate, but unlike viruses, do not infect other computer program files. Worms can create copies on the same computer, or can send the copies to other computers via a network. Worms often spread via IRC (Internet Relay Chat), but mainly via email that contain infected attachments.
  
• exe files: An executable file; as contrasted with a document or data file. Usually, executed by double-clicking its icon or a shortcut on the desktop, or by entering the name of the program at a command prompt. Executable files can also be executed from other programs, batch files or various script files. Transport of these files through the DCS Mail System is not allowed.
  
• com files: A type of executable file limited to 64 kb. These simple files are often used for utility programs and small routines. Because COM files are executable, viruses can infect them. This file type has the extension COM.Transport of these files through the DCS Mail System is not allowed.
  
• mp3 files: Moving Picture Experts Group Audio Layer 3 File. MP3 files are highly compressed audio tracks, and are very popular on the Internet. MP3 files are not programs, and viruses therefore generally cannot infect them. This file type has the extension MP3.
  
• Operating system: The operating system is usually the underlying software that enables you to interact with the computer. The operating system controls the computer storage, communications and task management functions. Examples of common operating stems include: MS-DOS, MacOS, Linux, Windows 98. Also: OS, DOS
  
• Virus Hoax: Hoaxes are not viruses, but are usually deliberate or unintentional e-messages warning people about a virus or other malicious software program. Some hoaxes cause as much trouble as viruses by causing massive amounts of unnecessary e-mail.
  
  Most hoaxes contain one or more of the following characteristics:
  
  • Warnings about alleged new viruses and its damaging consequences,
  • Demands the reader forward the warning to as many people as possible,
  • Pseudo-technical "information" describing the virus,
  • Bogus comments from officials: FBI, software companies, news agencies, etc.
  
  If you receive an e-mail message about a virus, check with a reputable source to ensure the warning is real.
  
• zip files: ZIP Archive File. A ZIP archive contains compressed collections of other files. ZIP files are popular on the Internet because users can deliver multiple files in a single container; the compressed files also save disk space and download time. A ZIP file can contain viruses if any of the files packaged in it contain viruses, but the ZIP file itself is not directly dangerous. Other archive files include RAR, and LHA files. This file type has the extension ZIP. Transport of these files through the DCS Mail System is not allowed.
  
• bat files: Text files containing one MS-DOS command on each line of the file. When run, each line executes in sequential order. The batch file AUTOEXEC.BAT is executed when the computer is booted and loads a series of controls and programs. This file type has the extension BAT. Transport of these files through the DCS Mail System is not allowed.
  
• Email spoofing: Email spoofing is the act of forging the header information on an email so that it appears to have originated from somewhere other than its true source. Email spoofing is used by virus authors. By propagating a virus with a spoofed email source it is more difficult for users who receive the virus to track its source to stop the virus. Email spoofing is also used by distributors of spam to hide their identity.
  
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