The term black fax refers to a
prank
A practical joke, or prank, is a mischievous trick played on someone, generally causing the victim to experience embarrassment, perplexity, confusion, or discomfort.Marsh, Moira. 2015. ''Practically Joking''. Logan: Utah State University Press. ...
fax transmission, consisting of one or more pages entirely filled with a uniform black tone. The sender's intention is generally to use up as much of the recipient's fax ink,
toner
Toner is a powder mixture used in laser printers and photocopiers to form the printed text and images on paper, in general through a toner cartridge. Mostly granulated plastic, early mixtures only added carbon powder and iron oxide, however, ...
, or thermal paper as possible, thus costing the recipient money, as well as denying the recipient use of their own machine (similar to computer-based
denial of service
In computing, a denial-of-service attack (DoS attack) is a cyber-attack in which the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host conne ...
attacks). This is made easier because
fax transmission protocols compress the solid black image very well, so a very short fax call can produce many pages.
Black faxes have been used to harass large institutions or government departments, to retaliate against the senders of
junk fax
Junk faxes are a form of telemarketing where unsolicited advertisements are sent via fax transmission. Junk faxes are the faxed equivalent of spam or junk mail. Proponents of this advertising medium often use the terms ''broadcast fax'' or ''fax a ...
es, or merely as simple pranks.
The basic principle of a black fax can be extended to form a ''black fax attack.'' In this case, one or more sheets are fed halfway through the sender's fax machine and taped end to end, forming an endless loop that cycles through the machine. Not only can solid black be used, but also images which will repeat endlessly on the receiver's machine until its toner runs out.
The introduction of
computer-based facsimile systems (combined with integrated document imaging solutions) at major corporations now means that black faxes are unlikely to cause problems for them. On the other hand, the ability of computer modems to send faxes offers new avenues for abuse. A program could be used to generate hundreds of pages of highly compressed, pure black – or huge volumes of relevant-looking, original, non-repeating high-black-density junk, just as effective but far more difficult to counteract – and send them very quickly to the target fax machine.
Black faxes and fax loops are similar (in both intention and implementation) to
lace cards.
See also
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Zip bomb
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Denial-of-service attack
In computing, a denial-of-service attack (DoS attack) is a cyber-attack in which the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host conne ...
*
List of practical joke topics
This is a list of practical joke topics (also known as a prank, gag, jape or shenanigan) which are mischievous tricks or jokes played on someone, typically causing the victim to experience embarrassment, perplexity, confusion, or discomfort.
Pra ...
References
{{reflist
External links
Black Faxat WordSpy
Description of Black Faxing in court documents (Page 7, Section 6)
Practical jokes
Fax
Sabotage
Denial-of-service attacks