Are Trojans that, upon execution, connect the system to a pay-per-call location in which the unsuspecting user is billed for the call without his/her knowledge. Dialers often arrive in porn-related or other enticing service-related applications.

Dialers are a type of software typically used by vendors serving pornography via the Internet. Once dialer software is downloaded, the user is disconnected from their modem's usual Internet service provider, re-connected to another Internet service provider (new dial-up telephone number), and the user is billed at exorbitant rates. Dialers do not "spy" on their intended victims, but these malevolent programs can rack up significant long distance phone charges, costing victims time and money.

have the ability to disconnect a computer from its Internet provider and reconnect it to the Internet using a toll or an international phone number.