There's no precise count that I know of, but it is possible to make a
reasonable estimate of the number of computers infected by viruses
Though the world probably hasn't quite hit the billion-computer-users
mark yet, it's awfully close. A lot of PCs enter the market each
year, and more and more people around the world have access to a
computer and to the internet. Each year, industry ships about 150-200
million brand new desktops, laptops and servers.
Given these huge numbers, it seems reasonable to suppose that about
500 million computers are in use with internet access around the
How many of these become infected with viruses?
There are no comprehensive accounts of the number of virus infections
worldwide, but we can make some educated guesses. The numbers are
doubtless large...a single virus can infect upwards of 10 million
users around the world!
According to the latest FBI statistics on cybercrime, 52% of computer
users (mostly from the business community) experienced some sort of
unathorized use or intrusion of their computer systems (down from a
high of 70% of users in 2000).
Of those unauthorized uses, 65% were virus attacks (a survey by
Microsoft found similar, but somewhat higher, numbers of computer
In other words, out of 1,000 computers, about 520 were subject to some
sort of unauthorized use or attack.
Out of those 520 computers, 65% of them were infected by viruses.
This amounts to 338 computers out of every 1,000.
Put another way, about 33.8%, or roughly a third, of all computers are
victims of virus attacks each year.
With our estimate of 500 million computers in the world, we can
calculate that there are [ 500 million * 0.338 ] =
169 million computers
infected with viruses around the world.
I trust this estimated number meets your needs. But if there's
anything else I can do for you, just let me know by posting a Request
for Clarification, and I'm at your service (as long as my computer
remains virus-free, that is!).
A billion PC users on the way
August 2, 2004
CSI/FBI COMPUTER CRIME AND SECURITY SURVEY
Microsoft's Malware Report: 60 Percent of PCs Infected
Blaster worm could have infected over 8 million PCs
April 5, 2004
search strategy -- Used bookmarked links to cybercrime sites, along
with Google searches on combinations of terms:
million PCs infected