VBS/Jer is a VBScript worm.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
Once excuted, the worm copies itself to the Windows System directory as "jer.htm". It modifies the registry so that the worm will be executed each time the system is restarted.
Then it disables several components from the Windows desktop, such as find, shutdown and network properties. It tries to change the Windows version to "VBS.GinSenG", the registered owner to "I Lovel You, Min" and the registered organizition to "GinsengBoy 2000".
In addition, it replaces the "script.ini" file from the mIRC directory to spread itself when an user joins the same channel where the infected user is. Furthermore, when the infected user is connecting to the IRC server, the worm joins to channel "#pioneer" and sends a message to that channel: "Another user infected by GinsengBoy -- haha".
Finally, it attempts to send itself using Outlook with the following message header:
Subject: Jer Resume Body: I would really like to get a new job. Please check out my resume. Enjoy :-) GinsengBoy Attachment: Jer.htm
However, this fails due to a bug.
The worm contains following commented lines on the top of its code:
' VBS.GinSenG - by OnG ' Thanks for the help on this one ;-P '
Technical Details: Katrin Tocheva and Sami Rautiainen, F-Secure