Wednesday, January 28, 2009

Defending Cell Phones and PDAs Against Attack: Cyber Security Tip ST06-007

Cyber Security Tip ST06-007
Defending Cell Phones and PDAs Against Attack (View the article with links to related articles)

As cell phones and PDAs become more technologically advanced, attackers are
finding new ways to target victims. By using text messaging or email, an
attacker could lure you to a malicious site or convince you to install
malicious code on your portable device.

What unique risks do cell phones and PDAs present?

Most current cell phones have the ability to send and receive text messages.
Some cell phones and PDAs also offer the ability to connect to the internet.
Although these are features that you might find useful and convenient,
attackers may try to take advantage of them. As a result, an attacker may be
able to accomplish the following:
* abuse your service - Most cell phone plans limit the number of text
messages you can send and receive. If an attacker spams you with text
messages, you may be charged additional fees. An attacker may also be
able to infect your phone or PDA with malicious code that will allow
them to use your service. Because the contract is in your name, you will
be responsible for the charges.
* lure you to a malicious web site - While PDAs and cell phones that give
you access to email are targets for standard phishing attacks, attackers
are now sending text messages to cell phones. These messages, supposedly
from a legitimate company, may try to convince you to visit a malicious
site by claiming that there is a problem with your account or stating
that you have been subscribed to a service. Once you visit the site, you
may be lured into providing personal information or downloading a
malicious file (see Avoiding Social Engineering and Phishing Attacks for
more information).
* use your cell phone or PDA in an attack - Attackers who can gain control
of your service may use your cell phone or PDA to attack others. Not
only does this hide the real attacker's identity, it allows the attacker
to increase the number of targets (see Understanding Denial-of-Service
Attacks for more information).
* gain access to account information - In some areas, cell phones are
becoming capable of performing certain transactions (from paying for
parking or groceries to conducting larger financial transactions). An
attacker who can gain access to a phone that is used for these types of
transactions may be able to discover your account information and use or
sell it.

What can you do to protect yourself?

* Follow general guidelines for protecting portable devices - Take
precautions to secure your cell phone and PDA the same way you should
secure your computer (see Cybersecurity for Electronic Devices and
Protecting Portable Devices: Data Security for more information).
* Be careful about posting your cell phone number and email address -
Attackers often use software that browses web sites for email addresses.
These addresses then become targets for attacks and spam (see Reducing
Spam for more information). Cell phone numbers can be collected
automatically, too. By limiting the number of people who have access to
your information, you limit your risk of becoming a victim.
* Do not follow links sent in email or text messages - Be suspicious of
URLs sent in unsolicited email or text messages. While the links may
appear to be legitimate, they may actually direct you to a malicious web
* Be wary of downloadable software - There are many sites that offer games
and other software you can download onto your cell phone or PDA. This
software could include malicious code. Avoid downloading files from
sites that you do not trust. If you are getting the files from a
supposedly secure site, look for a web site certificate (see
Understanding Web Site Certificates for more information). If you do
download a file from a web site, consider saving it to your computer and
manually scanning it for viruses before opening it.
* Evaluate your security settings - Make sure that you take advantage of
the security features offered on your device. Attackers may take
advantage of Bluetooth connections to access or download information on
your device. Disable Bluetooth when you are not using it to avoid
unauthorized access (see Understanding Bluetooth Technology for more

Author: Mindi McDowell

Produced 2006 by US-CERT, a government organization.

Note: This tip was previously published and is being re-distributed
to increase awareness.

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