Marburg is a polymorphic virus that only infects computers with a Windows 95 operating system installed. In addition, Marburg infects PE files, thus increasing their size.

When a file infected by this virus is executed, all PE files in the current directory and in the SYSTEM directory will be infected.

Marburg does not spread automatically using its own means. It needs the attacking user's intervention in order to reach the affected computer. The means of transmission used include, among others, floppy disks, CD-ROMs, e-mail messages with attached files, Internet downloads, FTP, IRC channels, peer-to-peer (P2P) file sharing networks, etc.

Depending on the system date stamp of the infected computer, and three mosnths after the infection, if an infected file is run at the same time when the infection took place, Marburg displays a presentation screen with several icons:

This screen consists of Windows 95 error icons (a white cross inside a red circle).