Madman is a simple TSR, EXE infector. The virus body is encrypted with 16bit variable XOR key. The virus infects EXE files during the DOS close function.
Depending on the settings of your F-Secure security product, it will either automatically delete, quarantine or rename the suspect file, or ask you for a desired action.
More information on the scanning and removal options available in your F-Secure product can be found in the Help Center.
You may also refer to the Knowledge Base on the F-Secure Community site for more information.
The virus activates when ctrl-alt-del is used. First it displays a close-up ascii picture of a face and then it displays the following message and waits for a keypress:
Nothing can save you here, friend - you're in my world now!
The virus also modifies batch files by adding an ECHO line at their end:
@ECHO I'm watching you!
The virus also contains the text 'MadMan'.