Absolute PC Security and Privacy.pdf

Viruses that replicate themselves via e-mail or over a computer network cause the subsidiary
problem of increasing the amount of Internet and network traffic. These fast-replicating
viruses—called worms—can completely overload a company network, shutting down servers
and forcing tens of thousands of users offline. While no individual machines might be
damaged, this type of communications disruption can be quite costly.
As you might suspect, most viruses are designed to deliver their payload when they’re first
executed. However, some viruses won’t attack until specifically prompted, typically on a
predetermined date or day of the week. They stay on your system, hidden from sight like a
sleeper agent in a spy novel, until they’re awoken on a specific date; then they go about the
work they were programmed to do.
In short, viruses are nasty little bits of computer code, designed to inflict as much damage as
possible, and to spread to as many computers as possible—a particularly vicious combination.
The History of Computer Viruses
Where, exactly, do computer viruses come from To answer that question, it’s helpful to
examine the history of computer viruses.
Technically, the concept of a computer virus was first imagined in 1949, well before
computers became commonplace. In that year, computer pioneer John von Neumann wrote a
paper titled “Theory and Organization of Complicated Automata.” In this paper, von
Neumann postulated that a computer program could be self-replicating—and thus predicted
today’s self-replicating virus programs.
The theories of von Neumann came to life in the 1950s, at Bell Labs. Programmers there
developed a game called “Core Wars,” where two players would unleash software
“organisms” into the mainframe computer, and watch as the competing programs would vie
for control of the machine—just as viruses do today.
In the real world, computer viruses came to the fore in the early 1980s, coincident with the
rise of the very first personal computers. These early viruses were typically spread by users
sharing programs and documents on floppy disks; a shared floppy was the perfect medium for
spreading virus files.
The first virus “in the wild,” as they say, infected Apple II floppy disk in 1981. The virus
went by the name of Elk Cloner, and didn’t do any real damage; all it did was display a short
rhyme onscreen:
It will get on all your disks
It will infiltrate your chips
Yes it’s Cloner!
It will stick to you like glue
It will modify ram too
Send in the Cloner!
At the time, Elk Cloner wasn’t identified as a virus, because the phrase “computer virus” had
yet to be coined. That happened in 1983, when programmer Len Adleman designed and