Sunday is a computer virus (program file virus), a member of the

Jerusalem Jerusalem (; he, יְרוּשָׁלַיִם ; ar, القُدس ) (combining the Biblical and common usage Arabic names); grc, Ἱερουσαλήμ/Ἰεροσόλυμα, Hierousalḗm/Hierosóluma; hy, Երուսաղեմ, Erusałēm. i ...

virus family. It was discovered in November 1989 after a number of simultaneous reports from

Seattle, Washington Seattle ( ) is a seaport city on the West Coast of the United States. It is the seat of King County, Washington. With a 2020 population of 737,015, it is the largest city in both the state of Washington and the Pacific Northwest region ...

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

, and surrounding areas. Several other Seattle outbreaks, including AirCop, were later traced to Asia.

Infection

Sunday is a standard patched Jerusalem variant in the way it infects files. It is a type of program file virus. It is a directly modified version of the original Jerusalem.1803. It infects .

EXE Exe or EXE may refer to: * .exe, a file extension * exe., abbreviation for executive Places * River Exe, in England * Exe Estuary, in England * Exe Island, in Exeter, England Transportation and vehicles * Exe (locomotive), a British locomotive ...

, . COM, and files. Like the original Jerusalem, infected files occasionally become corrupted.

Symptoms

Sunday is less easily identified than the original Jerusalem, in part because of corrected errors and in part because its payload is poorly written and fails to execute. *COM and EXE files increase by size. COM files increase by a set amount, while EXE files increase by somewhere between that amount and 9 or 10 bytes less. Unlike the original Jerusalem, files will not be infected many times. *

Interrupt In digital computers, an interrupt (sometimes referred to as a trap) is a request for the processor to ''interrupt'' currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted, ...

21 will be hooked. *Infected files will contain the string "Today is SunDay! Why do you work so hard? All work and no play make you a dull boy! Come on! Let's go out and have some fun!" The capitalization of "Sunday" is reported variously as "Sunday" or "SunDay", and may depend on the variant. Because of an error in coding, the virus fails to execute its payload, intended to set off on Sundays of every year other than 1989. This is to print the previously indicated text on the screen and then delete all files run while the virus is memory resident, as the original Jerusalem did every Friday the 13th.

Prevalence

The WildList, an organisation tracking computer viruses, listed Sunday as spreading in various forms from shortly after the list was started until 1998. Like all DOS viruses, Sunday suffered with the debut of

Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for ser ...

. It is now considered obsolete, although the virus was common enough that the use of previously dormant files has resulted in recent infections. However, anything other than a localised outbreak is unlikely.

References

{{reflist DOS file viruses