Ad adware program not updating
Often these programs get installed along with other programs you've loaded.
Of course, there's probably some sort of notification within the software's licensing agreement.
While some see this as a fair tradeoff--you get free software, the software-maker gets to observe your habits--others find it deceptive and invasive.
The Bitdefender Adware Removal Tool "eliminates annoying apps, adware, toolbars and other browser add-ons," claims a company press statement, but also "provides complete protection against malicious programs that can hijack computers." We're not sure how it does the latter, since adware-removal tools are typically much less robust than full-fledged antivirus software.
"Disconnect the PC from the Internet, and then disable the antivirus for the duration of the scan.
If your antivirus is unable to detect the threats by itself, chances are that it isn't working properly anyway." The Malwarebytes company recently released a full-fledged antivirus program, confusingly called Malwarebytes Anti-Malware Premium.
However, these agreements tend to be quite long, and most of us don't read them in their entirety.
In a typical scenario, spyware or adware gets bundled with freeware you download from the Internet.