The worm spreads in a email messages with the following contents:
Subject:
RE: Korea Japan ResultsBody: Take a look at these results ... Regards,
[current user's name]
Attachment:
koreajapan.chm
The attachment name vary and could be different.
If the user executes the attached file, the following screen is displayed:
Enable ActiveX To See Korea Japan results
The script in the compiled HTML help file will be executed when the user answer "Yes" in a dialog box.
After that Chick.F searches on C:, D: and E: drives for "script.ini" file from mIRC installation directory and if find such, the worm sends via mIRC with a filename "koreajapan.chm" previously saved into Windows installation directory.
The worm uses as an infection marker value 1 in the following registry key:
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\chm
and if it is set then it does not spread anymore from infected machine. Therefore Chick.F sends an infected message only to the first recipient found in the first address book.