It came as a Y2KCount.EXE file attached to a message supposedly sent from Microsoft support. The message looked like that:
Subject: Microsoft Announcement
Date: Wed, 15 Sep 1999 00:49:57 +0200
To All Microsoft Users,
We are excited to announce Microsoft Year 2000 Counter. Start the countdown NOW. Let us all get in the 21 Century.
Let us lead the way to the future and we
will get YOU there FASTER and SAFER.
The email was definitely faked, but the trick worked and a number of users launched the attachment and became infected. The attachment - Y2KCount.EXE is a self-extracting ZIP archive that contains installation pack for the new Internet trojan. The archive has 5 files (PROJECT1.EXE and 4 DAT files) and the PROJECT1.EXE file serves as an installer for the trojan. When run the Y2KCount.EXE shows a fake error message:
This is a disguise. At the same time the trojan installs itself to system. It copies 4 files into \Windows\System\ directory:
Then the SYSTEM.INI file is modified so that the trojan could be automatically started during next Windows bootup. The trojan adds 'ntsvsrv.dll' string after the list of drivers to start (after 'drivers=' tag). During next Windows startup the NTSVSRV.DLL gets control and renames WSOCK32.DLL to NLHVLD.DLL and copies PROCLIB16.DLL as WSOCK32.DLL. This will allow the trojan to monitor Internet activities on the infected system.
Being active the trojan checks Internet traffic for text strings 'login', 'password' and 'username'. This is done to get user's dial-up and network passwords. This action is typical for password stealing trojans.
F-Secure provides detection and removal of Y2KCount trojan with the latest updates that can be downloaded from our ftp site free of charge:
You can also try to manually remove the trojan from your system. This should be done only from DOS. The following 4 trojan files should be deleted from \Windows\System\ folder:
The 'ntsvsrv.dll' string (trojan startup command) should be removed from SYSTEM.INI file. You can edit this file using EDIT comand at DOS prompt. The trojan execution string follows other drivers to be started after 'drivers=' tag (it should be the last in the list in case of recent infection). Finally the NLHVLD.DLL should be renamed to WSOCK32.DLL. This will restore Windows Sockets library renamed by the trojan. After that the system should be restarted for the changes to take effect.