Wardialing (or war dialing) is a technique to automatically scan a list of

telephone A telephone, colloquially referred to as a phone, is a telecommunications device that enables two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most ...

numbers, usually dialing every number in a local area code to search for modems, computers,

bulletin board system A bulletin board system (BBS), also called a computer bulletin board service (CBBS), is a computer server running list of BBS software, software that allows users to connect to the system using a terminal program. Once logged in, the user perfor ...

s ( computer servers) and

fax machine Fax (short for facsimile), sometimes called telecopying or telefax (short for telefacsimile), is the telephonic transmission of scanned printed material (both text and images), normally to a telephone number connected to a printer or other out ...

s. Hackers use the resulting lists for various purposes: hobbyists for exploration, and crackers—malicious hackers who specialize in breaching computer security—for guessing user accounts (by capturing voicemail greetings), or locating modems that might provide an entry-point into computer or other electronic systems. It may also be used by security personnel, for example, to detect unauthorized devices, such as modems or faxes, on a company's telephone network.

Process

A single wardialing call would involve calling an unknown number, and waiting for one or two rings, since answering computers usually pick up on the first ring. If the phone rings twice, the modem hangs up and tries the next number. If a modem or fax machine answers, the wardialer program makes a note of the number. If a human or answering machine answers, the wardialer program hangs up. Depending on the time of day, wardialing 10,000 numbers in a given area code might annoy dozens or hundreds of people, some who attempt and fail to answer a phone in two rings, and some who succeed, only to hear the wardialing modem's carrier tone and hang up. The repeated incoming calls are especially annoying to businesses that have many consecutively numbered lines in the exchange, such as used with a

Centrex Centrex is a portmanteau of central exchange, a kind of telephone exchange. It provides functions similar to a PBX, but is provisioned with equipment owned by, and located at, the telephone company premises. Centrex service was first install ...

telephone system. Some newer wardialing software, such as WarVOX, does not require a modem to conduct wardialing. Rather, such programs can use

VOIP Voice over Internet Protocol (VoIP), also known as IP telephony, is a set of technologies used primarily for voice communication sessions over Internet Protocol (IP) networks, such as the Internet. VoIP enables voice calls to be transmitted as ...

connections, which can speed up the number of calls that a wardialer can make. Sandstorm Enterprises has a patent on a multi-line war dialer. ("System and Method for Scan-Dialing Telephone Numbers and Classifying Equipment Connected to Telephone Lines Associated therewith.") The patented technology is implemented in Sandstorm's PhoneSweep war dialer.

Etymology

The popular name for this technique originated in the 1983 film '' WarGames''. In the film, the protagonist programmed his computer to dial every telephone number in

Sunnyvale, California Sunnyvale () is a city located in the Santa Clara Valley in northwestern Santa Clara County, California, United States. Sunnyvale lies along the historic El Camino Real (California), El Camino Real and U.S. Route 101 in California, Highway 1 ...

to find other computer systems. Prior to the movie's release, this technique was known as "hammer dialing" or " demon dialing", but the film introduced the method to many, such as the members of

The 414s The 414s were a group of computer hackers from Milwaukee who broke into dozens of high-profile computer systems, including ones at Los Alamos National Laboratory, Sloan-Kettering Cancer Center, and Security Pacific National Bank, in 1982 and 1 ...

. By 1985 at least one company advertised a "War Games Autodialer" for Commodore computers. Such programs became common on bulletin board systems of the time, with file names often truncated to wardial.exe and the like due to length restrictions of 8 characters on such systems. Eventually, the etymology of the name fell behind as "war dialing" gained its own currency within computing culture. The popularity of wardialing in 1980s and 1990s prompted some states to enact legislation prohibiting the use of a device to dial telephone numbers without the intent of communicating with a person.

Variants

A more recent phenomenon is wardriving, the searching for

wireless network A wireless network is a computer network that uses wireless data connections between network nodes. Wireless networking allows homes, telecommunications networks, and business installations to avoid the costly process of introducing cables int ...

s (

Wi-Fi Wi-Fi () is a family of wireless network protocols based on the IEEE 802.11 family of standards, which are commonly used for Wireless LAN, local area networking of devices and Internet access, allowing nearby digital devices to exchange data by ...

) from a moving vehicle. Wardriving was named after wardialing, since both techniques involve actively scanning to find computer networks. The aim of wardriving is to collect information about

wireless access point In Computer networking device, computer networking, a wireless access point (WAP) (also just access point (AP)) is a networking hardware device that allows other Wi-Fi devices to connect to a wired network or wireless network. As a standalone ...

s (not to be confused with piggybacking). Similar to war dialing is a port scan under TCP/IP, which "dials" every TCP

port A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Hamburg, Manch ...

of every

IP address An Internet Protocol address (IP address) is a numerical label such as that is assigned to a device connected to a computer network that uses the Internet Protocol for communication. IP addresses serve two main functions: network interface i ...

to find out what services are available. Unlike wardialing, however, a port scan will generally not disturb a human being when it tries an IP address, regardless of whether there is a computer responding on that address or not. Related to wardriving is warchalking, the practice of drawing chalk symbols in public places to advertise the availability of wireless networks. The term is also used today by analogy for various sorts of exhaustive

brute force attack In cryptography, a brute-force attack or exhaustive key search is a cryptanalytic attack that consists of an attacker submitting many possible Key (cryptography), keys or passwords with the hope of eventually guessing correctly. This strategy can ...

against an authentication mechanism, such as a password. While a

dictionary attack In cryptanalysis and computer security, a dictionary attack is an attack using a restricted subset of a keyspace to defeat a cipher or authentication mechanism by trying to determine its decryption key or passphrase, sometimes trying thousands or ...

might involve trying each word in a dictionary as the password, "wardialing the password" would involve trying every possible password. Password protection systems are usually designed to make this impractical, by making the process slow and/or locking out an account for minutes or hours after some low number of wrong password entries.

References

{{reflist

External links

47 C.F.R. § 64.1200(a)(7)
The Electronic Code of Federal Regulations has the most up to date version of the TCPA which appears to make wardialing a federal crime in the United States.
Old School Hacks: War Dialing with WarVox
2009 article about using WarVOX for an internal network scan. Telephony Computer security exploits Phreaking

Process

Etymology

Variants

See also

References

External links