Unsolicited (aka junk) email is a big problem. I've written about such email in a previous edition of Security UPDATE (see "Tired of Unwanted Email? Try This Simple Solution"). Solicitors can find your email addresses many ways, some of which involve mining data from public news groups and Web-based message forums.
Other methods of obtaining your email address involve intrusive software packages that include various types of data mining, such as copying your contact list or address book contents. Such software is typically referred to as "spyware." For one example of how others gather data about you and those you know, read the Security UPDATE commentary "Protect Your Contact List: Read the EULA!".
To help protect yourselves from some kinds of spyware, you need to take several actions. First, don't let Java-based or ActiveX-based code run on your systems through your Web browser and email client software unless you're certain you can trust the content provider not to spy on your system. Second, you need to scan your systems from time to time to determine whether any known spyware might have slipped onto your system.
One great tool to help scan your systems for spyware is Lavasoft's Ad-Aware. Lavasoft recently released Ad-Aware 6.0. Although other available tools perform similar tasks, the basic version of Ad-Aware 6.0 does a great job and is free.
Ad-Aware scans your system's registry and file systems looking for keys and files that match known spyware programs. When Ad-Aware finds such an item, you can have the software remove it from your system. One useful feature of Ad-Aware is its ability to check for new spyware signature update files. For example, as of February 10, Ad-Aware scans for 4375 known spyware programs.
You must pay for the two more advanced versions of Ad-Aware: Ad-Aware Plus will scan for spyware in realtime and help prevent it from entering your system in the first place. Ad-Aware Professional can perform scans of remote systems and contains many additional features. For complete details about each version check the Lavasoft Web site \[http://www.lavasoft.de\] and click on the specific product.
Another useful tool for spyware identification is the SpyChecker.com Web site. The site maintains a database and search engine in which you can enter a name to determine whether it's listed as a spyware program or vendor.
Eliminating spyware from your systems won't eliminate junk email, but it will probably help you keep the amount of unwanted junk mail you receive to a minimum. It will also help keep marketing companies from snooping on your system to learn your Internet use habits without your knowledge and consent.