Class Virus
Platform Win16

Technical Details

It is a very dangerous memory resident parasitic virus. When an infected
program is executed, the virus infects the Windows KERNEL file. When an
infected KERNEL is executed, the virus hooks the WinExec function and
writes itself to the end of NewEXE files that are executed.

To infect the KERNEL the virus gets the access to that file by using
documented function GetModuleHandle, then the virus writes its code to the
KERNEL file (KRNL286.EXE or KRNL386.EXE), and patches the system data in
that file so, that the address of WinExec routine in the infected KERNEL
points to the virus code. Then the virus returns the control to the host
NewEXE file. So, when the infected file is executed, the virus infects only
the KERNEL file.

When the system with infected KERNEL is loading, the virus stays memory
resident as a part of KERNEL code, and patched WinExec address points to
the virus handler. When an NewEXE file is executed, the virus infects it.

The virus separates the infected and not infected files by using the
ID-label “LROY” that the virus writes to the checksum field in NewEXE
header while infecting a file.

Depending on the system date and the day number the virus displays the
message box bearing the title:

Chicago 7: Cyber riot

and the messages inside. The virus displays different messages, in April
starting from 29th and on May 1st:

Happy anniversary, Los Angeles!
Anarchists of the world, unite!

On any Friday before the 13th of a month:

When the levee breaks, I have no place to stay…
(Crying won’t help you. Praying won’t do you no good.)

On March 6 and in December from 1st to 26th:

Save the Whale, harpoon a fat cat.

After displaying the message, the virus erases disk sectors.

The virus also contains the text strings:

USER KERNEL Chicago-7 CyberRiot, 15.1.1993 Klash (Werner L.)
Sommer 1993: 15 Windowscomputerviren
Coming soon: Diet riot. Same great aftertaste–fewer bytes.
Source code avaiable for $15,000,000. Serious inquiries only.
Why does IBM need to lay me off? Oh well, their loss.
McAfee’s FUD equation: !!!!!!+??????=$$$$$$
Convict the pigs
This program was written in the cities of Hamburg, Chicago, Seattle and
Berkeley. Copyright (C) 1993 Klash/Skism/George J/Phalcon/Henry Buscombe
and 2 ex-Softies, collectively known as the Chicago 7.