Worm/Mydoom.CJ - Worm

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Summary

Full description

Statistics

Virus:	Worm/Mydoom.CJ
Date discovered:	18/08/2007
Type:	Worm
In the wild:	Yes
Reported Infections:	Medium
Distribution Potential:	Medium
Damage Potential:	Medium
Static file:	No
File size:	~22.000 Bytes
VDF version:	6.39.01.16 - Sat, 18 Aug 2007 18:25 (GMT+1)
IVDF version:	6.39.01.17 - Sat, 18 Aug 2007 18:25 (GMT+1)

General Method of propagation:
   • Email

Aliases:
   • F-Secure: Email-Worm:W32/Mytob.FP
   • Grisoft: I-Worm/Mydoom.DH

Platforms / OS:
   • Windows 98
   • Windows 98 SE
   • Windows NT
   • Windows ME
   • Windows 2000
   • Windows XP
   • Windows 2003

Side effects:
   • Uses its own Email engine
   • Registry modification
   • Third party control

Files It copies itself to the following location:
   • %SYSDIR%\mzupdate.exe

It copies itself within an archive to the following location:
   • %TEMPDIR%\tmp%hex number%.tmp

It deletes the initially executed copy of itself.

The following files are created:

– A file that is for temporary use and it might be deleted afterwards:
   • %TEMPDIR%\tmp%hex number%.tmp

Registry The following registry key is added in order to run the process after reboot:

– [HKLM\Software\Microsoft\Windows\CurrentVersion\Run]
• mzupdate = %SYSDIR%\mzupdate.exe

Email It contains an integrated SMTP engine in order to send emails. A direct connection with the destination server will be established. The characteristics are described in the following:

From:
The sender address is spoofed.
Generated addresses. Please do not assume that it was the sender's intention to send this email to you. He might not know about his infection or might not even be infected at all. Furthermore it is possible that you will receive bounced emails telling you that you are infected. This might also not be the case.

To:
– Email addresses found in specific files on the system.
– Generated addresses

Subject:
One of the following:
   • RE: hey, how are ya?
   • RE: long time no see!
   • Urgent Announcement
   • Important Announcement
   • RE: hey, hows it going?
   • RE: Your details
   • Hey, congratulations!
   • RE: You have been Approved

In some cases the subject might also be empty.
Furthermore the subject line could contain random letters.

Body:
– In some cases it may be empty.
– In some cases it may contain random characters.

The body of the email is one of the lines:
   • See attached document for details.
   • Please see attached document for more information.
   • This message could not be displayed. It has been attached to this email instead.
   • Please open the attached document. It contains important information.

Attachment:
The filename of the attachment is constructed out of the following:

– It starts with one of the following:
   • Readme
   • UrgentInfo
   • Details
   • New_Message
   • New_Document
   • %random character string%

    The file extension is one of the following:
   • .exe
   • .zip

The attachment is a copy of the malware itself.

The attachment is an archive containing a copy of the malware itself.

The email may look like one of the following:

Mailing Search addresses:
It searches the following files for email addresses:
   • wab
   • adb
   • tbb
   • dbx
   • asp
   • php
   • sht
   • htm

Address generation for TO and FROM fields:
To generate addresses it uses the following strings:
   • sandra; linda; julie; jimmy; jerry; helen; debby; claudia; brenda;
      anna; alice; brent; adam; ted; fred; bill; stan; smith; steve; matt;
      dave; dan; joe; jane; bob; robert; peter; tom; ray; mary; serg; brian;
      maria; leo; jose; andrew; george; david; kevin; mike; sam; james;
      john; jim; jack

It combines this with domains from the following list or from addresses found in files on the system

The domain is one of the following:
   • hotmail.com
   • yahoo.com
   • msn.com
   • aol.com

Avoid addresses:
It does not send emails to addresses containing one of the following strings:
   • accoun; certific; listserv; ntivi; support; icrosoft; admin; page;
      the.bat; gold-certs; feste; submit; not; help; service; privacy;
      somebody; soft; contact; site; rating; bugs; you; your; someone;
      anyone; nothing; nobody; noone; webmaster; postmaster; samples; info;
      root; mozilla; utgers.ed; tanford.e; pgp; acketst; secur; isc.o;
      isi.e; ripe.; arin.; sendmail; rfc-ed; ietf; iana; usenet; fido;
      linux; kernel; google; ibm.com; fsf.; gnu; mit.e; bsd; math; unix;
      berkeley; foo.; .mil; gov.; .gov; ruslis; nodomai; mydomai; example;
      inpris; borlan; sopho; panda; hotmail; msn.; icrosof; syma; avp; .edu;
      -._!; -._!@; abuse; www

Prepend MX strings:
In order to get the IP address of the mail server it has the ability to prepend the following strings to the domain name:
   • gate.
   • ns.
   • relay.
   • mail1.
   • mxs.
   • mx1.
   • smtp.
   • mail.
   • mx.

Backdoor Contact server:
The following:
   • io.phat********** : 7001

Sends information about:
    • Current malware status

Remote control capabilities:
    • Delete file
    • Download file
    • Execute file
    • Terminate malware

File details Programming language:
The malware program was written in MS Visual C++.

Runtime packer:
In order to aggravate detection and reduce size of the file it is packed with the following runtime packer:
• Petite

See a brief description here.

Description inserted by Andrei Gherman on Mon, 20 Aug 2007 09:00 (GMT+1)
Description updated by Andrei Gherman on Mon, 20 Aug 2007 10:11 (GMT+1)

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