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Adialer (American English) ordialler (British English) is an electronic device that is connected to atelephone line to monitor the dialed numbers and alter them to seamlessly provide services that otherwise require lengthynational orinternational access codes to be dialed. A dialer automatically inserts and modifies the numbers depending on the time of day, country or area code dialed, allowing the user to subscribe to the service providers who offer the best rates. For example, a dialer could be programmed to use one service provider for international calls and another for cellular calls. This process is known as prefix insertion orleast cost routing. A line-powered dialer does not need any external power but instead takes the power it needs from the telephone line.
Another type of dialer is acomputer program which creates a connection to theInternet or anothercomputer network over the analogtelephone orIntegrated Services Digital Network (ISDN). Manyoperating systems already contain such a program for connections through thePoint-to-Point Protocol (PPP), such asWvDial.
Manyinternet service providers offer installation CDs to simplify the process of setting up a properInternet connection. They either create an entry in the operating system's dialer or install a separate dialer (as theAOL software does).
In recent years, the term "dialer" often refers specifically to dialers that connect without the user's full knowledge as to cost, with the creator of the dialer intending to commitfraud.
Call centres use various forms of automatic dialler to place outbound calls to people on contact lists.
Dialers are necessary to connect to the internet (at least for non-broadband connections), but some dialers are designed to connect to premium-rate numbers. The providers of such dialers often search forsecurity holes in theoperating system installed on the user's computer and use them to set the computer up to dial up through their number, so as to make money from the calls. Alternatively, some dialers inform the user what it is that they are doing, with the promise of special content, accessible only via the special number. Examples of this content include software for download, (usuallyillegal)trojans posing asMP3s, trojans posing aspornography, or 'underground' programs such ascracks andkeygens.
The cost of setting up such a service is relatively low, amounting to a few thousand dollars for telecommunications equipment, whereupon the unscrupulous operator will typically take 90% of the cost of a premium rate call, with very few overheads of their own.
Users withDSLs (or similarbroadband connections) are usually not affected. A dialer can be downloaded and installed, but dialing in is not possible as there are no regular phone numbers in the DSL network and users will not typically have their dial-up modem, if any, connected to a phone line. However, if anISDN adapter or additional analogmodem is installed, the dialer might still be able to get a connection.
Malicious dialers can be identified by the following characteristics:[citation needed]
Computers running Microsoft Windows without anti-virus software or proper updates could be vulnerable toVisual Basic-scripts which install atrojan horse which changes values in theWindows Registry and setsInternet Explorer security settings in a way thatActiveX controls can be downloaded from the Internet without warning. After this change is made, when a user accesses a malicious page or email message, it can start installing the dialer. The script also disables themodemspeaker and messages that normally come up while dialing into anetwork. Users ofMicrosoft Office Outlook,Outlook Express andInternet Explorer are especially affected if runningActiveX controls andJavaScript is allowed and the latest security patches fromMicrosoft have not been installed. In March 2004, there were malicious dialers that could be installed through fakeanti-virus software.[citation needed]E-mail spam from a so-called "AntiVirus Team" for example, contained download links to programs named "downloadtool.exe" or "antivirus.exe", which are malicious dialers. Other ways of transmission include electronic greeting cards that link to pages that tricks the user to installActiveX controls, which in turn install dialers in the background.
Therefore, links inspam emails should never be opened, automatically starteddownloads should be canceled as soon as discovered, and one should check on each dial-up to the Internet to see whether the displayed phone number is unchanged. Another way to protect oneself is to disable premium numbers through one'sphone services, but of course this disables all such services.
One should never run foreign code in a privileged environment unless the source is trustworthy. It is also advisable to protect oneself with anti-malware programs.
On 15 August 2003, a new law came into effect inGermany called "Gesetz zur Bekämpfung des Missbrauchs von (0)190er/(0)900er Mehrwertdiensterufnummern" ("Law for the combat of misuse of (0)190/(0)900 value added service numbers").
The law contains the following regulations:
On 4 March 2004 theGermanFederal Supreme Court inKarlsruhe decided that fees for the usage of dialers do not have to be paid if it was used without the user's knowledge.
