Skip Navigation
 Search | Directories | Reference Tools
UW Home > UWIN > Computing and Networking 

E-postcards endanger your computer

Date: August 14, 2007

The UW is receiving a large and increasing number of a new type of dangerous email. Email messages that say "a postcard is waiting for you, just click here," or something similar, are trying to entice you to visit a Web site capable of attacking your computer.

Do not click on any links or go to any Web addresses in such messages!

Your computer is likely to be attacked by sophisticated programs designed to search for weaknesses in your computer's configuration and use them to inject viruses or bot programs into your computer. Simply visiting the Web page will cause an attack, even without clicking on anything in the page.

Although up-to-date, well-maintained computers with current anti-virus software are less vulnerable, even they might be infected by such sites.

What do they look like?

A recent fake postcard message had the following text:

         Subject: Animated postcard
         School friend(tht_2020@shaw.ca) has created Animated postcard 
         for you at xxxxxx.com.
         To see your custom Animated postcard, simply click on the 
         following link:
            http://xx.xx.xxxx.x/
         Send a FREE greeting card from xxxxxx.com whenever 
         you want by visiting us at xxxxxx.com
         This service is provided and hosted by xxxxxx.com.

Because these messages are simple text (which varies from message to message) and do not contain any recognizable viruses themselves, they are difficult for anti-virus and anti-spam programs to identify. UW UW Technology is constantly updating the attack and virus detection systems for UW Email to try to stop as many of these messages a possible, but large numbers are still getting through.

How do these attacks work?

Called "drive-by attacks" or "drive-by downloads" these attacks are particularly dangerous because simply visiting a page can cause an attack and the attack can take place without any apparent indication to the computer user.

When you visit a Web page with the attack code embedded in it, the attack program uses security flaws (if found) in your browser to quickly and systematically check for hundreds of possible weaknesses in your computer. If any are found, a file is uploaded, infecting your computer. Some of the uploaded programs are likely to be "bots," programs that run on an infected computer and can respond to commands sent from elsewhere on the Internet. Such bots are responsible for a large part of email spam. The presence of such infections is often not apparent to the computer user and may even be hidden from any anti-virus programs the computer is running.

Questions

How can I tell if a postcard message is good or bad?
You should be suspicious of ANY email message containing WEB addresses! Anything about the message (wording, colors, graphics, logos, etc.) can be faked. That said, if the message is expected and is like legitimate messages you have received before, it MAY be legitimate.

What can I do to prevent a drive-by attack?
For all kinds of computers, install all the operating system and software updates as soon as they become available. Many of the updates address the known vulnerabilities the attack programs are looking for. Also, install and run an anti-virus program (faculty, staff, and students can download McAfee anti-virus free) and keep up with up with all the data file updates.

More Information