Computer security history – classic DOS virus identification This virus, famous for activating on Friday the 13th, infects both .EXE and .COM files and deletes any program executed on that date. What is its widely known name?

Introduction / Context:
Before modern operating system protections, DOS-era file-infecting malware spread rapidly through floppy disks and early networks. Several classic viruses became notorious for their trigger conditions. Recognizing famous signatures helps in understanding malware taxonomy and historical incident response.

Given Data / Assumptions:

• The virus infects both .EXE and .COM files.
• It activates specifically on Friday the 13th.
• On that date it deletes programs that are run.

Concept / Approach:
The described behavior matches the Jerusalem virus family (also called Friday the 13th). It originated in the late 1980s, infected executable formats, and had a destructive payload on the trigger date. Other listed malware are from different eras or have different behaviors.

Step-by-Step Solution:
Match the trigger: Friday the 13th is a hallmark of the Jerusalem family.Confirm file types: .COM and .EXE infection is consistent with classic DOS file infectors like Jerusalem.Eliminate options that belong to different platforms or payload characteristics.

Verification / Alternative check:
Virus encyclopedias and historical writeups describe Jerusalem’s Friday-the-13th destructive routine and its multi-file infection pattern.

Why Other Options Are Wrong:

• Chernobyl (CIH): late-1990s Windows virus that overwrote flash BIOS on certain dates; not specific to Friday the 13th.
• Melissa: 1999 email macro virus that spread via Microsoft Office documents; no Friday-the-13th trigger.
• I Love You: 2000 email worm in VBScript; social engineering based, not a .COM/.EXE file infector.
• Michelangelo: triggered March 6; different signature and date.

Common Pitfalls:
Confusing similarly notorious names across decades. Always tie the identifying trigger (date) and file types to the correct family.

Final Answer:
Jerusalem