Antispyware programs are a lot like antivirus applications:
- Both essentially consist of a scanning engine that relies on signatures files (also known as definitions or fingerprints) to detect spyware and adware.
- Once a scan detects potentially harmful files, the antivirus or antispyware software will either ask you how it should handle the detections or remove or quarantine them automatically.
- More comprehensive antispyware applications offer real-time protection akin to what antivirus programs offer. Real-time protection monitors critical checkpoints in Windows.
- Antispyware software is designed to prevent the installation of both spyware and adware, in a manner similar to how antivirus protection blocks viruses, worms, and Trojans from installing.
- Any antivirus and antispyware software - and by extension, the protection they offer - is only as good as their latest definitions. These types of programs need constant updating. The frequency of new signature (and software) updates varies with the manufacturer, but it can be as often as every few days for antispyware signatures.
- Like antivirus software, some of the more comprehensive antispyware scanning engines use heuristic (rules-based) technology to detect new and unknown threats for which signatures are yet to be released. That is, they use rules based on experience to look for software that is likely to be viruses or spyware
- Free versions of well-regarded programs are available. However, these usually have less features and/or limited capabilities than their for-sale counterparts.
- Antivirus and antispyware applications are now commonly bundled with firewalls and other privacy tools as part of security suites.
There is one HUGE difference between antivirus and antispyware software
Antispyware software, as a group, does not come close to matching the performance and track record of antivirus applications. For instance, venerable products like Norton Antivirus and McAfee Viruscan block and/or remove nearly every virus they are expected to protect against. In addition their heuristic technology helps protect against unknown quantities!. By contrast, the best antispyware programs have a success rate of approximately 75%. That means they still allow an awful lot of nasties to get through.
The mediocre performance is a testament to the creativity and persistence of the folks creating spyware. But it also betrays the absence of reference standards that can be applied across the board, facilitating the comparison of products from different manufacturers and the creation of a unified front in the war against spyware.
Because even the best antispyware program only protects against roughly three-quarters of known threats, many security experts recommend installing two or three antispyware applications, with one of them providing real-time protection. The thinking behind this strategy is that spyware "getting by" one application might be detected by the other.
Fortunately, this is another area where antivirus and antispyware software differ: While running more than one antivirus (or firewall) program at a time is a recipe for trouble, the same is not true for antispyware applications. Experience suggests that you can run multiple programs with real-time protection without conflict, or even a noticeable degradation in your computer's performance.
