Virus & Security

 

Due to viruses on computers within our university network, slowdowns and interruptions are frequently experienced in internet usage, file sharing, and printer-sharing workgroups.

In order to prevent these slowdowns and disruptions, all staff using the university network are required to install antivirus software on their computers with proper care, keep this software regularly updated, and continuously monitor operating system updates.

Brief information about what viruses are and what effects they may cause is provided below.

WHAT IS A COMPUTER VIRUS?

Viruses, Trojans, and Worms

In the mid-1980s, two Pakistani brothers who were software developers learned that their programs were being copied without permission. In response, they wrote a program that copied itself onto every floppy disk used by their customers. This program also contained a copyright message. In this way, the first computer virus was created.

This simple beginning later led to the development of a broad antivirus culture. Today, new viruses can spread across the world within minutes, damaging data, slowing down network connections, and harming reputations.

What is a Virus?

A virus or worm is a computer program that can spread through computers and networks by copying itself, often without the user’s knowledge. Viruses can have harmful effects. These can range from displaying annoying messages on your screen to giving control of your computer to other users.

How Do Viruses Infect Computers?

For a virus to infect your computer, it must first be executed. Viruses use many methods to achieve this. They can embed themselves inside other programs or disguise themselves so that they automatically run when certain file types are opened. Sometimes they exploit vulnerabilities in the operating system to execute themselves and spread automatically.

You can get a virus from an email attachment, a file downloaded from the internet, or a disk. Once the file is opened, the virus code starts running. The virus then copies itself into other files or disks and may make changes to your computer.

 

Trojans

Trojans are programs that appear to be legitimate and proper software but actually perform hidden and harmful actions. For example, DLoader-L arrives via email and presents itself as a new update for Microsoft Windows XP. However, when executed, it downloads a program that allows your computer to connect to certain websites. Its purpose is to overload these websites by sending more connection requests than they can handle, attempting to crash them (this is called a denial of service attack).

Trojans do not replicate themselves, so they cannot spread as quickly as viruses. However, they often work together with viruses. Viruses can download Trojans that steal information or record keystrokes. Trojans can also be used to infect a computer with a virus.

 

Worms

Worms are similar to viruses but do not require a document or program to carry them. They replicate themselves and spread by using network connections between computers. Viruses like MyDoom or Bagle can also behave like worms and spread through email.

 

What Can Viruses Do?

In the past, viruses would either play April Fools’ jokes on your computer or, in the worst case, make your computer unusable. However, today they threaten your security in much different ways.

  • Email slowdown: Email-worm viruses such as Sobig can generate so much email traffic that mail servers become extremely slow or even crash. In such cases, system administrators may shut down the server to reduce the risk of a full failure.
  • Stealing sensitive information: Worms like Bugbear-D can record keystrokes and steal passwords (for example, those used for online banking), allowing the attacker to access this information.
  • Attacking websites: MyDoom used infected computers to send large amounts of traffic to the SCO software company’s website, making it unusable (a denial of service attack).
  • Allowing remote access: Some viruses install backdoor Trojans on your computer, allowing attackers to connect to your system and use it for their own purposes.
  • Corrupting data: The Compatable virus modifies information in Excel files, making data unusable.
  • Deleting data: The Sircam worm can delete or overwrite everything on your hard drive on a selected day.
  • Disabling hardware: CIH (also known as Chernobyl) can overwrite your BIOS chip on April 26, rendering your computer unusable.
  • Annoying pranks: The Netsky-D worm caused infected computers to beep for hours one morning.
  • Displaying messages: Cone-F displays political messages on the screen when May arrives.
  • Damaging reputation: If a virus spreads from your computer to others, your email may be blocked or you may even face claims for damages.
  • Embarrassment: For example, PolyPost registers your documents and name in adult-themed newsgroups.