Adware

Alternatively called malware, pitchware, sneakware, or spyware, adware is a program installed without a user's consent or knowledge during the install of another program. Much like spyware, adware tracks individuals Internet activities and habits to help companies advertise more efficiently.
Adware is usually installed on a computer with free programs because the developers are often paid if they include it with their program. Like spyware, adware can be located and removed from a computer using software utilities available on the Internet.
Protecting a computer from adware
A computer can be infected by adware by visiting an infected website, downloading infected software, or installing infected software. Most antivirus programs can clean adware, but it's also a good idea to run an anti-malware or malware cleaner, such as Malwarebytes.
Botnet, Malvertisement, Malware, OptOut, Ransomware, Security terms, Software, Software terms, Spyware, Trojan, Ware, Worm