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.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
Description Created: Mikko Hypponen, F-Secure