Type File virus
Date Discovered 1991.04
Place of Origin Bulgaria
Source Language Assembly
Platform DOS
File Type(s) .com
Infection Length 45 bytes
Reported Costs

Mini, also known as Trivial is a family of the smallest viruses ever created. Some variants of this virus get as small as 13 bytes. It was featured in The Giant Black Book of Computer Viruses by Mark Ludwig, who used a 44-byte variant as an example of the simplest virus possible.


When a Mini infected file is executed, the virus infects all .com files in the current directory. It will not change the size of the file unless it was already under 45 bytes, in which case, the file will grow to that size. Infected files may be damaged and it is possible that neither the original program nor the virus will execute properly.


There are hundreds of variants of the Mini virus. All have the same functionality of simply overwriting .com files. The smallest is only 13 bytes long. A few go into the hundreds.

Other Facts

Dr. Mark Ludwig used this virus as an example of an extremely simple virus in his book The Giant Black Book of Computer Viruses. In addition to describing the virus, the chapter devoted to it gives instructions on how to create a similar virus and gives the reader some exercises for making similar viruses.


Mark A. Ludwig. The Giant Black Book of Computer Viruses, Chapter 3 "The Simplest COM Infector", pp. 27-37. American Eagle Publications: Show Low, Arizona. 1998

Patricia Hoffman. Online VSUM, Mini-45 Virus.

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