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Discovered: March 02, 2004
Updated: March 03, 2004 10:29:40 PM
Systems Affected: Windows

W32.Beagle.J@mm is a mass-mailing worm that opens a backdoor on TCP port 2745 and uses its own SMTP engine to spread through email. It also sends the attacker the port on which the backdoor listens, as well as the IP address. The email attachment is a randomly named .exe file inside a .zip file. The embedded .exe file is password-protected with a random password.

W32.Beagle.J@mm also attempts to spread across file-sharing networks, such as Kazaa and iMesh, by dropping itself into the directories that contain "shar" in their names.

Technical Description

W32.Beagle.J@mm is a mass-mailing worm that installs a backdoor on infected systems. The worm arrives via email attachment in a message with a spoofed from address. The address may be one of the following:
management@<recipient domain>
administration@<recipient domain>
staff@<recipient domain>
noreply@<recipient domain>
support@<recipient domain>

It may use one of the following subjects:

E-mail account disabling warning.
E-mail account security warning.
Email account utilization warning.
Important notify about your e-mail account.
Notify about using the e-mail account.
Notify about your e-mail account utilization.
Warning about your e-mail account.

Message body can be one of the following:
Dear user of <domain>,
Dear user of <domain> gateway e-mail server,
Dear user of e-mail server "<domain>",
Hello user of <domain> e-mail server,
Dear user of "<domain>" mailing system,
Dear user, the management of <domain> mailing system wants to let you know that,

Followed by one of the following paragraphs:

Your e-mail account has been temporary disabled because of unauthorized access.
Our main mailing server will be temporary unavaible for next two days,
to continue receiving mail in these days you have to configure our free
auto-forwarding service.
Your e-mail account will be disabled because of improper using in next
three days, if you are still wishing to use it, please, resign your
account information.
We warn you about some attacks on your e-mail account. Your computer may
contain viruses, in order to keep your computer and e-mail account safe,
please, follow the instructions.
Our antivirus software has detected a large ammount of viruses outgoing
from your email account, you may use our free anti-virus tool to clean up
your computer software.
Some of our clients complained about the spam (negative e-mail content)
outgoing from your e-mail account. Probably, you have been infected by
a proxy-relay trojan server. In order to keep your computer safe,
follow the instructions.

Followed by one of the following lines:
For more information see the attached file.
Further details can be obtained from attached file.
Advanced details can be found in attached file.
For details see the attach.
For details see the attached file.
For further details see the attach.
Please, read the attach for further details.
Pay attention on attached file.

Followed by:
The <domain> team http://www.<domain>

Followed by one of the following lines:
The Management,
Best wishes,
Have a good day,
Kind regards,

Followed by one of the following lines:
For security reasons attached file is password protected. The password is "<password>".
For security purposes the attached file is password protected. Password is "<password>".
Attached file protected with the password for security reasons. Password is <password>.
In order to read the attach you have to use the following password: <password>.

Note: <domain> is the domain name part of the reciever address. <password> is a 5-digit random number that the worm used to encrypt the attached zip file.

The attachment name will be one of the following names with a .zip or .pif extension:

If the attachment is a .zip file, it contains a randomly named executable file.

When run, the worm will create the following files:
irun4.exeopen is a .zip file with password protection. The password is randomly assigned and is included in the text portion of the mail message.

The following registry entry is created:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\ssate.exe = %System%\irun4.exe

The worm opens a backdoor on TCP port 2745.

The backdoor port number and IP address of the infected host are then communicated to one of three webservers listening on TCP port 80 of:

If an attacker sends a specially formatted data message to the port, the worm will allow an arbitrary file to be downloaded to the %Windir% folder. This file will be saved as %Windir%\iuplda<x>.exe, where <x> is a random string of characters.

It then attempts to terminate the following processes:

Following this, files with the following extensions are scanned for e-mail addresses:

The worm then uses its SMTP engine to transmit copies of itself to the e-mail addresses that were discovered. The worm has its own MIME implementation. It will not send itself to any email addresses that include the following strings:

Finally, the icon used for the attachment may fool unsuspecting users into believing that the attachment is a WordPad document.

The worm also attempts to propagate through filesharing networks by creating the following copies of itself in folders with the string "shar" in their names:
ACDSee 9.exe
Adobe Photoshop 9 full.exe
Ahead Nero 7.exe
Matrix 3 Revolution English Subtitles.exe
Microsoft Office 2003 Crack, Working!.exe
Microsoft Office XP working Crack, Keygen.exe
Microsoft Windows XP, WinXP Crack, working Keygen.exe
Opera 8 New!.exe
Porno pics arhive, xxx.exe
Porno Screensaver.scr
Porno, sex, oral, anal cool, awesome!!.exe
WinAmp 5 Pro Keygen Crack Update.exe
WinAmp 6 New!.exe
Windown Longhorn Beta Leak.exe
Windows Sourcecode update.doc.exe
XXX hardcore images.exe