Brief History of Malware
With the emergence of computers, malware arose from the dark side. UNIX computers were the first targets. In the 1970s and 1980s, programs known as rootkits were developed.1 Those who hack systems with criminal intent, known as black hats, used these applications to hide their presence while they had their way with an unsuspecting organization's infrastructure.
The first personal computer malware category to arise was viruses. As early as 1982, high school student Rich Skrenta wrote a gem called "Elk Cloner" for Apple II computers.2Yes, the first known virus targeted an Apple computer. At the time, it was probably the biggest target.
As malware defense matured, so did malware sophistication. Other types of malicious programs emerged, including those which could propagate without any help from the user population. Known as worms, they are probably today's biggest challenge to malware defense.
And the black hats have been busy. Over the years, the malware count has risen exponentially--and continues to do so. Figure 1 depicts malware growth through May 2009.3
The statistics shown are from AV-Test.org, a company that tests the effectiveness of anti-virus software, and formatted by PC Magazine. They show an accelerating increase in the number of unique malware applications since 2007. There is no evidence this growth will stop.
Early malware was written by hackers trying to make a name for themselves within the black hat community. Today, malware is used by individual black hats as well as crime syndicates to make money--to transfer your money to criminals' bank accounts around the world.
Now that I have your attention, let's look at each of the types of malware as we explore the question, what is malware?