The worm propagates automatically on Windows 9x and Windows NT platforms through email and has a destructive payload that triggers in the year 2000.

The worm propagates by automatically sending itself to as many as 50 people in the Outlook address book. The subject line is empty and the body of the email is:

Here's some pictures for you!

It will also contain a worm program attachment named pics4you.exe (34,304 bytes). It attempts to fool the recipient into believing that the attachment contains images. When the attachment is executed (pics4you.exe), the program will not display any images and simply seems to have terminated. But the worm will become resident in memory and will email itself to as many as 50 people. The worm will also set Microsoft Internet Explorer browser's 'Home Page' setting to:

http://www.geocities.com/SiliconValley/Vista/8279/index.html

The Windows registry keys will also be modified and changed to load the worm in memory every time the computer system is rebooted. As a result, the worm will always be resident in memory.

Payload

The worm has two payloads that simulate a Y2K problem.

After pics4you.exe is executed, the worm will remain resident in memory and monitor the system clock. When the worm detects the year 2000 (i.e. Jan 1, 2000), the worm will insert and execute a file named CBIOS.COM. The worm will also overwrite the autoexec.bat file.

The CBIOS.COM file is a 15-byte program written in assembly and designed to overwrite the high byte of the two-byte CMOS checksum value in the system BIOS. As a result, the computer will display a system BIOS error such as:

"CMOS Checksum Invalid"

When it is next cold rebooted. This problem can be corrected by launching the system BIOS setup utility and saving the BIOS data again. This will rewrite and recalculate the BIOS checksum value. The worm will overwrite the autoexec.bat with the following data:

ctty nul

format d: /autotest /q /u

format c: /autotest /q /u

The new autoexec.bat file size will be 64 bytes.

As a result, the data on both the C and D drives will be formatted.

Additional Notes

It is important to note that the worm has been written using Microsoft Visual Basic. In order for the worm to run, the worm is dependent on a Visual Basic Virtual Machine run-time library file named MSVBVM50.DLL that needs to be installed independent of the worm on the computer. The MSVBVM50.DLL does not propagate with the worm.

Repair Notes

To remove this worm manually, one should perform the following steps:

End the MYPICS task/process by pressing the Ctrl-Alt-Del keys. You should see a process called MYPICS. End the task/process.

Remove the following registry entry:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run= C:\Pics4You.Exe

HKEY_LOCAL_MACHINE\Software\Microsoft\WindowsNT\Windows\Run= C:\Pics4You.Exe

Check if the autoexec.bat file has been modified (this will only occur if the computers system clock is set to year 2000). If so, delete autoexec.bat and restore an original copy from backup.

Check if the CBIOS.COM file exists (this file will only exist if the computers system clock is set to year 2000). If so, delete the CBIOS.COM file.

From the Windows Start menu, select Find-Files or Folders and search for any program named Pics4you.exe and delete it.

The worm will alter the 'Home Page' in the Microsoft Internet Explorer browser. You will need to restore the original 'Home Page'.