Aplore is mass-mailing worm that spreads via Outlook and IRC. The
main component is written in Delphi and contains the IRC spreading
routines and an embedded web server.
When the worm is executed it copies itself to the Windows System
Directory as 'explorer.exe'. This copy is linked into the registry
to 'HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\Explorer' so
it will be started when Windows starts up.
The worm has an IRC engine inside and uses it to connect to a public
IRC server. It joins random channels and sends private messages to
users who join the channel. It offers a web link that points to
the infected machine.
The page on the URL says that the user has to download a plugin to
view the content.
The page has a REFRESH tag so in one second it offers the worm file
When the user chooses to run the file it starts and infects the system.
The spreading routine is in a Visual Basic file email.vbs that
the worm drops once the attached file is executed. When the Outlook
Application is closed by the worm, the script file is deleted.
The email messages that the worm sends look as follows:
F-Secure Anti Virus detects the script component of the worm using
heuristics and the rest of the worm files as I-Worm.Aphex
[Analysis: Katrin Tocheva and Gergely Erdelyi; F-Secure Corp.; April 9th, 2002]