The term “adware” refers to unwanted advertisement software that gets on the device against the user’s wishes, collects marketing information and displays advertisements that “interest” the user.
Such software differs from Trojans in that it is relatively harmless, i.e. it does not disrupt the main and auxiliary systems of the computer and does not steal confidential information. Its only disadvantage is the annoying display of unnecessary, annoying commercial ads on the screen.
Most often an adware gets on the device when the user allows installing a free software package, which includes software for displaying advertising offers. The default checkbox is not unchecked by the user simply due to inattention or agreement to install the recommended list.