Scan for PUPs

PUP stands for Potentially Unwanted Program.  While they are not necessarily malware, they are software programs that most people do not want on their system.  PUPs can add toolbars and extensions to your browser window, install other programs, change your home page and search settings, tell you that you have malware on your computer and need to pay money to have it removed, and even track everything you do to sell you targeted ads.

Most antivirus programs include the ability to scan for PUPs, but for many of them, this feature is disabled by default.  Here is a rundown of how to enable scanning for PUPs in some of the most common antivirus suites:

AVG - PUP scanning is enabled by default in AVG, but it is always a good idea to check and make sure it is on.  To check, click on "Options" from the AVG menu (upper-left corner) and select "Advanced Settings".  Then open the menu for "Computer Protection" and select "AntiVirus".  On the right side, you will see a box for "Report potentially unwanted programs and spyware threats" and one for "Report enhanced set of potentially unwanted program".  Ensure both are checked.

Avast - Avast has PUP scanning turned off by default.  To turn it on, go to "Settings" and select "Active Protection".  There are three categories of protection:  File System Shield, Mail Shield, and Web Shield.  For each one, click the "Settings" button (or the button that looks like a gear), choose the "Sensitivity" tab, and check the "Scan for potentially unwanted programs (PUPs)".  Click OK, and then go back and follow the same instructions for the other two shields.

Kaspersky - Kaspersky has PUP scanning turned off by default.  To turn it on, click the "Settings" link at the bottom left corner, select the "Additional" tab, and click on "Threats and Exclusions".  Check the "Detect other software that can by used by criminals to damage your computer or personal data" box.

McAfee - McAfee has PUP scanning turned on by default, but again, it is good to double-check.  Click on the "Schedule and Run Scans" link, then select "Real Time Scanning", and finally, select "Settings".  Under "Scan for These Threats", check the "Spyware and other potentially unwanted programs" box.

Norton - Norton's antivirus suite does not include the ability to scan for PUPs.