A Dialer is a piece of software which is designed to dial a telephone number automatically.
Automated dialers can store names and telephone numbers and enable the user to easily contact people without having to remember phone numbers, or to be tracked by Caller ID.
Most automated dialers will retrieve contact information from other databases, such as Microsoft Outlook Contacts list.
Some automated dialers will also dial a telephone number at regular intervals until a person answers the phone. When the person answers the telephone, the automated dialer will sound an alarm to let the caller know that the called party is on the line.
A spyware dialer is a malicious program that installs itself onto a computer and attempts to dial telephone lines at other locations, often incurring expensive phone bills for the victim. A dialer is different from the spyware typically bundled with free software downloads. They are however, difficult to detect and furthermore prove that the dialer is responsible for the charges. It is also difficult to distinguish a legitimate dialer from a spyware dialer, a factor that has made this infection much harder to control.<ref>Spyware Dialers Spamlaws.com</ref> Spyware dialers are however, easy to remove if the user can find the exact file where the spyware is located.