Beyond student virus-writers and purely criminal business in the Internet there are “grey” businesses - activities existing on the brink of law. Imposing electronic advertisement, utilities, offering user to visit this or that paid web-resource and other types of unwanted software — they all also require technical support of hacker programmer. It is requires to secretly intrude into the system, repetitive renewal of components and various masking (to protect from deletion from the system), resist anti-virus programs — these aims almost fully coincide with the functional of different Trojans.
Adware
Special advertising components penetrate the system, download advertising information from special servers and show it to the user. In most cases (but not always) the intrusion into the system happens unknown for the user and pop-ups appear only when the Internet-browser is operating (as advertising systems are masked as advertisement banners of web-sites).
After several USA states passed anti-advertisement regulations, Adware developers actually turned out to be beyond law (and practically all of them are American companies). Finally some of them legalized their developments to the maximum: Adware is currently supplied with an installator, there is an icon on the systems panel and a deinstallator. However, hardly any person of sound mind will be willing to install an advertising system on his computer, therefore legal Adware is ‘hard-sold’ together with some free software.
Adware is installed together with this software: most users click “OK”, ignoring texts (appearing) on the screen — and get advertising programs together with the ones being installed. As often a half of the desktop and system panel are filled with various icons, the icon of the advertisement program becomes lost among them. Thus Adware, legal de jure, is installed secretly from the user and is not seen in the system.
It should be noted that in some cases it is impossible to delete legal advertising systems without affection of operation of the main software. Thus producers of Adware protect it from deinstallation.
Pornography and premium-pay resources
To attract users to paid web-sites often different programs are used which de jure are not categorized as malicious as they do not conceal their presence, and the user appears on the paid resource having positively answered а corresponding question. However, installation of such is not authorized by the user, and for instance when the user visits dubious web-sites. Then they obtrusively offer (the user) to visit this or that paid resource.
Rogue antivirus and anti-spyware programs
This is a relatively new type of cybercrime. The user is fobbed off with a small program, which informs that spyware or virus has been detected on the computer. The message appears in any case regardless of the actual situation - even if no other programs except ОС Windows are installed on the computer. At the same time the user is offered to purchase a “treatment” for a small sum of money which in fact does not cure anything.
