System information

Threats to computer security 19
TYPE
NAME
DESCRIPTION
Email-
Worm
E-mail worms
E-mail worms infect computers via e-mail.
The infected message has an attached file
containing either a copy of a worm, or a link to a
worm file uploaded to a website. The website is
usually either one that has been hacked, or is
the hacker's own site. When the attachment is
opened the worm is activated; alternatively,
when you click the link, download and open the
file, the worm will become active. After this the
worm will continue reproducing by finding other
e-mail addresses and sending infected
messages to them.
IRC-
Worms
IRC worms
Worms of this type get into computers through
Internet Relay channels, which are used to
communicate with other people via the internet
in real time.
These worms publish on the internet chat
channel, either a copy of the worm file, or a link
to the file. When a user downloads and opens
the file, the worm will be activated.
Net-
Worms
Network worms
(worms residing in
computer
networks)
These worms are distributed via computer
networks.
Unlike other types of worms, network worms
propagate without the user's participation. They
search the local area network for computers
which host programs containing vulnerabilities.
They do this by broadcasting a special network
packet (exploit) containing its code or a part of
its code to each computer. If there is a
vulnerable computer in the network, it will be
infiltrated by the packet. Once the worm fully
penetrates the computer, it becomes active.