Need help? Ask the community or hire an expert.
Go to Avira Answers
Date discovered:21/03/2006
In the wild:Yes
Reported Infections:Low
Distribution Potential:Medium to high
Damage Potential:Medium
Static file:Yes
File size:28.160 Bytes
MD5 checksum:eda0ab20b95a3722b04101490D340E20
VDF version:

 General Methods of propagation:
   • Email
   • Peer to Peer

   •  Kaspersky: Email-Worm.Win32.Gurong.a
   •  TrendMicro: WORM_MYDOOM.BK

It was previously detected as:
   •  Worm/Mydoom.CD.2

Platforms / OS:
   • Windows 95
   • Windows 98
   • Windows 98 SE
   • Windows NT
   • Windows ME
   • Windows 2000
   • Windows XP
   • Windows 2003

Side effects:
   • Downloads a malicious file
   • Uses its own Email engine
   • Registry modification

 Files It copies itself to the following location:
   • %SYSDIR%\wmedia16.exe

It deletes the initially executed copy of itself.

The following files are created:

– Temporary files that might be deleted afterwards:
   • %TEMPDIR%\removeMe%number%.bat
   • %TEMPDIR%\tmp%hex number%.tmp

It tries to download a file:

– The locations are the following:
   • 65.19.**********
   • 64.62.**********
It is saved on the local hard drive under: c:\mp.exe Furthermore this file gets executed after it was fully downloaded. Further investigation pointed out that this file is malware, too. Detected as: Worm/Mydoom.CD.1

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

– [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   • WMedia16 = wmedia16.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:

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.

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

One of the following:
   • Re: I got it! Try it now!
   • Re[2]: wazzup bro
   • Re: Hello
   • Greetings!
   • Hey dear!
   • Hello friend ;)
   • Wazzap bro!!
   • Hey! How are you doing bud?

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

–  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:
   • Hey dear! Here is my photos, as I promised.
   • Hello bro! Here is my new girlfriend's photo! Check it out!
   • Hey man! Take a look at attachment!
   • Hello buddy! Take a look at attachment! Here is my nude 17-yr sister!
   • Whatz up man! There is my nude 17-yr sister in the attachment!
   • Greetings! Check out my portfolio, please! Here is some my photos in the archive.
   • Greetings. Here is some my nude photos in the attachment.
   • Hey bro! Check out attachment! There is a new plug-in for skype!
   • Hello! I sent you new skype plug-in, as you wished.
   • Hello! There is NEW plug-in for MSN. Try it out!
   • Hello! Here is NEW smiles pack for MSN messenger! It is really cool ;)
   • Hey friend! Try this new smiles pack for MSN messenger!

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

–  It starts with one of the following:
   • body
   • i_love_u
   • i_luv_u
   • conf_data
   • port_imgs
   • sex_pics
   • doc
   • sex_girls
   • document
   • %random character string%

    The file extension is one of the following:
   • .bat
   • .cmd
   • .exe
   • .pif
   • .scr
   • .zip

The email may look like one of the following:

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

Address generation for TO and FROM fields:
To generate addresses it uses the following strings:
   • john; john; alex; michael; james; mike; kevin; david; george; sam;
      andrew; jose; sandra; den; dmitry; vlad; alexey; olga; leo; maria;
      jim; brian; serg; mary; ray; tom; peter; robert; bob; jane; linda;
      craig; jayson; lee; cyber; frank; joe; dan; dave; matt; steve; smith;
      adam; brent; alice; anna; brenda; claudia; debby; helen; jerry; jimmy;
      julie; linda; marina; vladimir; nikolay; gerhard; ilya; boris

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:

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

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:
   • mx.
   • mail.
   • smtp.
   • mx1.
   • mxs.
   • mail1.
   • relay.
   • ns.
   • gate.

 P2P In order to infect other systems in the Peer to Peer network community the following action is performed:  

   It retrieves the shared folder by querying the following registry key:
   • HCKU\Software\Kazaa\Transfer\DlDir0

   If successful, the following files are created:
   • winamp5.bat; icq5.bat; xp_activation.bat; strip-girl4.bat0c.bat;
      dcom_patches.bat; lsas_patches.bat; msblast_patches.bat;
      skype_video.bat; 0day_patch.bat; office_crack.bat;
      trillian_crack_all.bat; winamp5.cmd; icq5.cmd; xp_activation.cmd;
      strip-girl4.cmd0c.cmd; dcom_patches.cmd; lsas_patches.cmd;
      msblast_patches.cmd; skype_video.cmd; 0day_patch.cmd;
      office_crack.cmd; trillian_crack_all.cmd; winamp5.exe; icq5.exe;
      xp_activation.exe; strip-girl4.exe0c.exe; dcom_patches.exe;
      lsas_patches.exe; msblast_patches.exe; skype_video.exe;
      0day_patch.exe; office_crack.exe; trillian_crack_all.exe; winamp5.pif;
      icq5.pif; xp_activation.pif; strip-girl4.pif0c.pif; dcom_patches.pif;
      lsas_patches.pif; msblast_patches.pif; skype_video.pif;
      0day_patch.pif; office_crack.pif; trillian_crack_all.pif; winamp5.scr;
      icq5.scr; xp_activation.scr; strip-girl4.scr0c.scr; dcom_patches.scr;
      lsas_patches.scr; msblast_patches.scr; skype_video.scr;
      0day_patch.scr; office_crack.scr; trillian_crack_all.scr;;;;;;;;;;;

   These files are copies of the malware itself.

 Miscellaneous Internet connection:

Checks for an internet connection by contacting the following web site:

It creates the following Mutex:
   • systemHNDLR9r21

 Rootkit Technology It is a malware-specific technology. The malware hides its presence from system utilities, security applications and in the end, from the user.

Hides the following:
– Its own file
– Its own process
– Its own registry key

Method used:
    • Hidden from Windows API

Hooks the following API functions:
   • NtClose/ZwClose
   • NtCreateFile/ZwCreateFile
   • NtEnumerateKey/ZwEnumerateKey
   • NtEnumerateValueKey/ZwEnumerateValueKEy
   • NtOpenFile/ZWOpenFile
   • NtQueryDirectoryFile/ZwQueryDirectoryFile

 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:
   • UPX

Description inserted by Andrei Gherman on Wednesday, March 22, 2006
Description updated by Andrei Gherman on Thursday, March 30, 2006

Back . . . .