Jerusalem Virus


The Jerusalem virus, also known as the Friday 13th virus, is a malicious computer program that was first identified in 1987 in Jerusalem. It is a memory-resident virus that infects .COM and .EXE files, often increasing their sizes and potentially causing system performance issues. The virus is also known to delete programs that are executed on a Friday the 13th, hence its alternate name.


The phonetic pronunciation of the keyword “Jerusalem Virus” is: “juːˈruːsələm ˈvaɪrəs”.

Key Takeaways

  1. The Jerusalem Virus, also known as the Friday the 13th virus, is one of the first known and most destructive computer viruses. It was discovered in 1987 in the city of Jerusalem, hence its name.
  2. This virus primarily infects .exe files and destroys them so completely that they cannot be recovered. It lurks in the background and significantly slows down the performance of affected computers. The level of damage and behavior may vary slightly with its different variants.
  3. One significant aspect of the Jerusalem virus is its notorious activation date. It lays dormant in a system until Friday the 13th, upon which it deletes every program that is run. This led to extensive data loss in infected systems.


The Jerusalem Virus, also known as the “Friday the 13th” virus, is significant in the field of technology because it was one of the earliest and most disruptive computer viruses ever detected. Originating from Israel in 1987, it gained its name due to its discovery at the Hebrew University of Jerusalem. The virus had a deadly effect on computers as it multiplied excessively, slowing down system performance, erasing files randomly, and more severely, deleting entire programs on every Friday the 13th, hence its alternate moniker. Understanding the nature of the Jerusalem virus has been fundamental to the development of better preventative cyber security measures against malicious software. Its detection highlighted the dire necessity for regular system checks, the creation of antivirus software, and the importance of safe internet habits.


The Jerusalem Virus, also known as the “Friday the 13th” virus, was a prolific computer virus first detected in the city of Jerusalem, in Israel, back in 1987. Its purpose, like many other computer viruses, was to disrupt the normal functions of a computer system, leading to potential data loss and overall system instability. It was particularly known for its destructive payload that it delivered on Friday the 13th, hence the nickname. The virus was programmed to delete executable files that were run on the infected computer on this particular day.The Jerusalem Virus’s purpose was primarily to carry out mischief and cause chaos. It was not intended to extract sensitive information or to control the infected systems remotely. Its main objective was to proliferate across as many systems as possible and trigger significant damage to the affected programs and files, leading to annoying disruptions for the users and potentially significant productivity and data loss. In this way, the Jerusalem Virus is representative of an era of malware designed for large-scale havoc rather than more modern, stealthy attacks aimed at data theft or espionage.


1. Spanish Vaccine Industry Incident: In December 1990, the Jerusalem virus impacted the Spanish vaccine industry by contaminating its computers and deleting numerous vital files. This caused significant disruption and delayed the distribution of vaccines in the country. 2. University of California, North Carolina: In April 1988, the Jerusalem virus infected the University of California’s computer systems. This resulted in a day-long shutdown of all computing services while the IT team worked to remove the virus and restore the infected files.3. Federal Aviation Administration (FAA): In 1992, the FAA reported the Jerusalem virus had infected their system. This impacted their operational efficiency and caused significant delays in processes until the issue was fixed.

Frequently Asked Questions(FAQ)

**Q: What is the Jerusalem Virus?**A: The Jerusalem Virus, also known as the Friday the 13th Virus, is a computer virus that first appeared in 1987. It was named after the city where it was first discovered. The virus typically becomes active and causes damage to the user’s computer data every Friday the 13th.**Q: How does the Jerusalem Virus spread?**A: The Jerusalem Virus spreads through infected files, usually executable files. If an infected file is run, the virus gets executed and infects the computer system.**Q: What are the symptoms of a Jerusalem Virus infection?**A: Symptoms can include a slowdown in system performance, software malfunction, altered program functionality, file corruption, and all programs and files being deleted on the Friday the 13th.**Q: What can the Jerusalem Virus damage?**A: The Jerusalem Virus can cause severe damage to the user’s system. It can delete all the files and programs on the machine when it becomes active, typically on Friday the 13th.**Q: How can I protect my computer from the Jerusalem Virus?**A: Protection from the Jerusalem Virus involves regular antivirus scans, keeping your software up to date, avoiding downloads from untrusted sources, and using preventative software.**Q: How is the Jerusalem Virus removed?**A: Once the Jerusalem Virus is detected, it can usually be removed using a reliable antivirus program. The user may need to scan the system multiple times to ensure complete removal.**Q: What kind of computers can the Jerusalem Virus infect?**A: The Jerusalem Virus primarily infects computers running the DOS operating system. However, adapted versions may potentially affect other operating systems as well.**Q: Are newer computers at risk from the Jerusalem Virus?**A: Today’s computers are relatively safe from the Jerusalem Virus due to antivirus software advancements and the discontinuation of DOS. However, remain vigilant as new variants of old viruses can sometimes appear.**Q: Can the Jerusalem Virus steal personal information?**A: The original version of the Jerusalem Virus was not designed to steal personal information, but instead to delete data. However, modified versions may potentially have additional capabilities.

Related Tech Terms

  • Malware
  • Computer Security
  • Virus Detection
  • Antivirus Software
  • Computing History

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