Type File virus
Creator Mad Satan
Date Discovered 1993
Place of Origin Taiwan
Source Language
Platform DOS
File Type(s) .com, .exe
Infection Length
Reported Costs

Madsatan is a memory resident virus from 1993. It infects .com and .exe files and has similarities to Jerusalem and Tamsui.

Table of Contents


When a file infected with Madsatan is executed, it becomes memory resident. It infects .com and .exe files as they are executed, appending itself to the end of the file.


Some variants of Madsatan are considered variants of Jerusalem depending on the antivirus product. One variant is sometimes considered a variant of Tamsui. The basics of all Jerusalem and Madsatan variants are the same (ability to infect .com and .exe files, memory residency). In fact, very few antivirus products acknowledge a large Madsatan family, one rare exception being Kaspersky. Others label the variants as individual viruses seperate from any family or as members of other families. However, they all have in common that they are signed by Mad Satan, a virus coder from Taiwan.

The virus also seems to have some relation to Badboy, as it is often listed as a variant of that virus by some antivirus products.

Different versions have different text strings in them. Some may also choose to only infect one type of file while memory resident.


Kaspersky Lab. SecureList, Virus.DOS.MadSatan.599. 2000.03.07

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License