Spyware, Viruses, Malware, Worms, Trojan Horses, and Adware: Symptoms, Solutions, and Prevention


A Virus or Computer Virus is a self-replicating program or piece of script or code that make copies of itself and then either attaches itself to an existing file on the infected system or store copies of itself on the system with innocuous sounding names like ‘repair tool’.

The virus is limited to spread itself only by either being transmitted or sent by an unwitting user or carried on a portable storage medium from one system to another. However, if a virus gets embedded somewhere on a network drive then anyone who opens or clicks on the infected document or file can end up getting infected as well.


Spyware is software that gathers information about a users Internet habits, browsing patterns, email passwords, usernames and even credit card information, in essence, ‘spying’ on the hapless user. This type of software usually gets installed without the knowledge of the user and can transmit the collected data to a third party over the Internet secretly as well.


Malware can refer to any number of malicious forms of software or code that has been intentionally designed to perform one or more of the following malicious acts:

> Infiltrate a users computer system without their consent.

> Gather sensitive personal information such as credit card numbers, social security numbers, birth dates, or system passwords.

> Create back doors or remote entry points to allow hackers access to the system.

> The destruction of critical data and/or corruption of system files.

Malware is a general term and is commonly used to include, Viruses, Worms, Spyware, Trojan Horses, and some forms of Adware. The actual intention of malware can vary but by definition it is any software that is destructive by nature. Because the term Malware is so broad it is hard to cite one specific source for the most infections.


A Worm or Computer Worm is a self-replicating piece of computer code that uses a computer network to spread copies of itself to the other nodes on the network. Unlike the Virus a Worm can accomplish this without any intervention or help from the user. Also unlike a Computer Virus the Worm does not have to attach itself to an existing computer program or file.

Many times a Worm will also be used to carry a ‘payload’. The ‘payload’ is code that is designed to perform some specific function. In some cases the payload allows the Worm to send documents through the email accounts of the infected system attaching itself and its payload to the email as an attachment. When the unsuspecting recipient of the email opens the attachment the process starts again.

Trojan Horse:

A Trojan or Trojan Horse Virus is a program that usually gets downloaded installed and executed on a computer system which then appears to be performing some useful function but is unknowingly allowing unauthorized access to the user’s computer system at the same time.

Hackers use Trojans to gain access to a user’s computer remotely and then perform any number of malicious activities. These nefarious activities can include but certainly are not limited to:

> Data Theft.

> Keystroke Logging.

> Downloading or Uploading Files.

> Viewing the Victims Screen.

> Crashing the Users System.


Adware is advertiser supported software that displays, plays or downloads advertisements either onto the computer desktop or into the computers web browser as a condition of the software installation. Most Adware is free to use as long as you don’t mind annoying pop-up windows appearing at random intervals advertising some product or another. I have seen some Adware that opened a new window about every 1 to 2 minutes, making it nearly impossible to use the system at all until the software had to be removed.

Additionally, Adware will almost always be collecting data about your Internet habits and browsing behavior to tailor ads specifically to best match the data recovered. In that respect it is actually very similar to many types of Spyware. In most cases Adware is simply a way to place advertisements in the face of the user although it’s a fine line before you could also classify it as Spyware.

With Adware however, in some cases you may actually be given a chance to review and choose whether or not to accept the terms and conditions associated with the software before installing it.


Symptoms of Infection:

> Very sluggish computer performance.

> Random system lockups or crashes.

> Browser redirection – you are taken to websites you were not searching for while browsing the Internet.

> Excessive number of popup windows appearing at random while surfing the Internet.

> You are informed that your system has ‘hundreds’ of active infections and you are redirected to a website that insists you pay for and download their specific software package to remove the infections.


There are many good anti-virus / anti-spyware products on the market designed to detect and remove these types of infections. McAfee and Kapersky are good but AVG and Avast! have similar products and offer a free downloadable version. Be sure to complete a ‘Full’ system scan and quarantine and remove all active infections. Configure your anti-virus software to perform ‘active’ scanning or real-time system monitoring.


> Do not install software you have downloaded from the Internet unless it has come from a known, reliable source.

> Use caution if using file sharing platforms such as LimeWire or torrent sites to download files.

> Do not open any email attachments from unknown sources.

> Use a good anti-virus/anti-spyware application and scan your system at least weekly. Be sure your anti-virus software is totally up to date with the latest virus definitions.

> For Windows users: Be sure to visit the Microsoft update site and download all the latest Microsoft security patches.