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328 Part Two Information Technology Infrastructure

Intruders also use the information they have gleaned to set up rogue access
points on a different radio channel in physical locations close to users to force
a user’s radio network interface controller (NIC) to associate with the rogue
access point. Once this association occurs, hackers using the rogue access point
can capture the names and passwords of unsuspecting users.

MALICIOUS SOFTWARE: VIRUSES, WORMS, TROJAN

HORSES, AND SPYWARE
Malicious software programs are referred to as malware and include a
variety of threats, such as computer viruses, worms, and Trojan horses. A
computer virus is a rogue software program that attaches itself to other
software programs or data files in order to be executed, usually without user
knowledge or permission. Most computer viruses deliver a “payload.” The
payload may be relatively benign, such as instructions to display a message or
image, or it may be highly destructive—destroying programs or data, clogging
computer memory, reformatting a computer’s hard drive, or causing programs
to run improperly. Viruses typically spread from computer to computer when
humans take an action, such as sending an e-mail attachment or copying an
infected file.
Most recent attacks have come from worms, which are independent
computer programs that copy themselves from one computer to other
computers over a network. Unlike viruses, worms can operate on their own
without attaching to other computer program files and rely less on human
behavior in order to spread from computer to computer. This explains why
computer worms spread much more rapidly than computer viruses. Worms
destroy data and programs as well as disrupt or even halt the operation of
computer networks.
Worms and viruses are often spread over the Internet from files of
downloaded software, from files attached to e-mail transmissions, or from
compromised e-mail messages, online ads, or instant messaging. Viruses
have also invaded computerized information systems from “infected” disks
or infected machines. Especially prevalent today are drive-by down-
loads, consisting of malware that comes with a downloaded file that a user
intentionally or unintentionally requests.
Hackers can do to a smartphone just about anything they can do to any
Internet device: request malicious files without user intervention, delete
files, transmit files, install programs running in the background to monitor
user actions, and potentially convert the smartphone into a robot in a botnet
to send e-mail and text messages to anyone. With smartphones starting to
outsell PCs, and smartphones increasingly used as payment devices, they are
becoming a major avenue for malware.
Malware targeting mobile devices is not yet as extensive as that targeting
larger computers, but nonetheless is spreading using e-mail, text messages,
Bluetooth, and file downloads from the Web via Wi-Fi or cellular networks.
The security firm McAfee found nearly 13,000 different kinds of malware
targeting mobile devices in 2012 compared to less than 2,000 in 2011, with
almost all attacks targeting devices using Google’s Android operating system.
(Graziano, 2012). Mobile device viruses pose serious threats to enterprise
computing because so many wireless devices are now linked to corporate
information systems.

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