Coronex

Coronex is a worm virus spreading via the Internet as an attachment to infected emails. The worm also copies itself to the "C:\My Downloads" directory that may cause other ways of spreading.

The worm itself is a Windows PE EXE file about 12KB in length and is written in Assembler.

The worm activates (from an infected email message) only when a user clicks on the attached file. If this happens the worm starts its installation and spreading routines.

Installing

While installing the worm copies itself to the Windows directory under the name "corona.exe" registers this file in the system registry auto-run key:

HKLM\Software\Microsoft\Windows\CurrentVersion\Run PC-Config32 = %WinDir%\corona.exe

The installation procedure contains bugs, therefore the worm often is not able to install itself into the system, however, despite this the worm is still able to activate its spreading routines.

Spreading: email

To send infected messages the worm uses a direct connection to the "ns.execulink.com" SMTP server. To get victim email addresses the worm scans the WAB database (Windows Address Book).

The worm activates its spreading routine once per hour (minute:seconds = 1:1).

Infected messages have different "From", "Subject", and "Message body" fields and "Attachment" file names:

'sars@hotmail.com' SARS Severe Acute Respiratory Syndrome sars.exe 'sars2@hotmail.com' I need your help Severe Acute Respiratory Syndrome corona.exe 'corona@hotmail.com' Virus Alert! SARS Virus virus.exe 'virus@yahoo.com' Corona Virus honk kong hongkong.exe 'deaths@china.com' bye deaths virus deaths.exe 'virus@china.com' SARS SEE Ya sars2.exe 'virus2@china.com' SARS Virus SARS Corona Virus cv.exe

Spreading: MyDownloads

The Coronex worm copies itself to "C:\My Downloads" using the following names:

'Cossacks Full Version.exe' 'Battlefield 1942 (full).exe' 'Warcraft III Full.exe' 'Jedi Knight II.exe' 'Quake 3 Full Version.exe' 'Starcraft full.exe' 'Doom 3.exe' 'Tribes 2 (full).exe' 'Rainbow 6 Full.exe' 'Oni full.exe' 'White and Black.exe' 'Return to Castle Wolfenstien (Full).exe' 'Command & Conquer: Generals.exe' 'Black Hawk Down (full).exe' 'The Sims: Unleashed.exe' 'Age Of Mythology.exe' 'Dark Age of Camelot.exe' 'Ultima Online.exe' 'The Lord of the Rings.exe' 'Medel Of Honor: Allied Assault.exe' 'Grand Theft Auto 3 (full).exe' 'Unreal 2: The Awakening (full).exe' 'Unreal.exe' 'Master Of Orion 3.exe'

After copying itself the worm increases its copy file length to several megabytes.

If there is no "C:\My Downloads" directory, the Coronex worm copies itself to current directory.