Sleepwalker stays resident in memory and infects all executed or opened COM files. It marks infected files by setting their time stamp to 10:47 (time field is not visible with normal DOS DIR command).
Sleepwalker contains the following text:
Sleepwalker. (C) OPTUS 1993.
Disinfection & Removal
Allow F-Secure Anti-Virus to disinfect the relevant files.
For more general information on disinfection, please see Removal Instructions.
Description Created: Mikko Hypponen, F-Secure