Email-Worm:W32/MyDoom.AE

Classification

Malware

Email-Worm

W32

MyDoom.AE, .Mydoom.AA

Summary

A new variant of MyDoom worm - Mydoom.AE, was found on October 16th, 2004. The worm is similar to previous variants. It downloads and executes an additional file from a website. This file is detected as 'Worm.P2P.Scranor'. The Scranor P2P (peer-to-peer) worm in its turn downloads and runs another file, that is detected as 'Backdoor.Win32.Rbot.gen'. The MyDoom.AE worm has a message from Mydoom author(s) to AV vendors.

Removal

Automatic action

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

Eliminating a Local Network Outbreak

If the infection is in a local network, please follow the instructions on this webpage:

Find out more

Knowledge Base

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User Guide

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Contact Support

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Submit a sample

Submit a file or URL for further analysis.

Technical Details

The worm is a PE executable file 51712 bytes long packed with UPX file compressor. The unpacked file's size is over 107 kilobytes.

Installation to system

When the worm's file is run, it first creates a mutex named 'My-Game'. Then the worm tries to download a file from the 'www.freewebs.com' website. This file is saved to the root folder of C: drive as 'Scran.exe' and is then activated. The downloaded file is a P2P (peer-to-peer) worm called 'Scranor'.

Upon installation the worm copies itself as 'avpr.exe' file to Windows System Directory and creates a startup key for that file in System Registry:

  • [HKLM\Software\Microsoft\Windows\CurrentVersion\Run] "Avpr" = "%WinSysDir%\avpr.exe"

where "%WinSysDir%" represents Windows System directory. If the startup key cal not be created in HKLM (local machine) Registry tree, it is created in HKCU (current user) tree.

Also the worm creates the following key in the Registry:

  • [HKLM\Software\Microsoft\Windows\DdInfect]

Spreading in emails

The worm spreads by sending its infected attachment to all email addresses found on an infected computer. The worm looks for email addresses in Windows Address Book and in the files with the following extensions:

  • wab
  • pl
  • adb
  • tbb
  • dbx
  • asp
  • php
  • sht
  • vbs
  • cfg
  • eml
  • cgi
  • wsh
  • msg
  • uin
  • xls
  • jsp
  • xml
  • mdx
  • mbx
  • html
  • htm
  • txt

The worm searches for these files in the following locations:

  • Desktop folder
  • Temporary Internet Files folder
  • My Documents folder
  • Application Data folders
  • Program Files folders
  • Windows System folder

The files are searched on hard disks and RAM drives from C: to Z:.

The worm avoids sending emails to email addresses that contain any of the following substrings:

  • avp
  • syma
  • icrosof
  • panda
  • sopho
  • borlan
  • inpris
  • example
  • mydomai
  • nodomai
  • ruslis
  • .gov
  • gov.
  • .mil
  • foo.
  • berkeley
  • unix
  • math
  • bsd
  • mit.e
  • gnu
  • fsf.
  • ibm.com
  • kernel
  • linux
  • fido
  • usenet
  • iana
  • ietf
  • rfc-ed
  • sendmail
  • arin.
  • ripe.
  • isi.e
  • isc.o
  • acketst
  • pgp
  • tanford.e
  • utgers.ed
  • mozilla
  • root
  • info
  • samples
  • postmaster
  • webmaster
  • noone
  • nobody
  • nothing
  • anyone
  • someone
  • your
  • you
  • me
  • bugs
  • rating
  • site
  • contact
  • soft
  • no
  • somebody
  • privacy
  • service
  • help
  • not
  • submit
  • feste
  • ca
  • gold-certs
  • the.bat
  • page
  • admin
  • icrosoft
  • support
  • ntivi
  • unix
  • bsd
  • linux
  • listserv
  • certific
  • google
  • accoun

The subject of infected emails is selected from the following variants:

  • Announcement
  • Details
  • Re:Details
  • Information
  • Re:Information
  • Important
  • Re:Important
  • Fw:Important
  • Document
  • Re:Document
  • Fw:Document
  • Notification
  • Re:Notification
  • Fw:Notification
  • Warning
  • Re:Warning
  • Fw:Warning
  • read now!
  • Information
  • Fw:Information

The body text of infected emails is selected from the following variants:

  • Daily Report.
  • your document.
  • here is the document.
  • Reply
  • Important Information.
  • Kill the writer of this document!
  • Details are in the attached document.
  • See the attached file for details
  • Please see the attached file for details
  • Check the attached document.
  • Monthly news report.
  • Please confirm!.
  • Please read the attached file!.
  • Please see the attached file for details.
  • Waiting for a Response. Please read the attachment.
  • Please answer quickly!.

The worm's attachment name is selected from the following variants:

  • document.doc <spaces> .
  • report.doc <spaces> .
  • news.doc <spaces> .
  • msg.doc <spaces> .
  • information.doc <spaces> .
  • letter.doc <spaces> .
  • message.doc <spaces> .
  • file.doc <spaces> .
  • check.doc <spaces> .
  • error.doc <spaces> .
  • archive.doc <spaces> .
  • list.doc <spaces> .
  • data.doc <spaces> .
  • text.doc <spaces> .
  • note.doc <spaces> .
  • notes.doc <spaces> .
  • attachment.doc <spaces> .

The extension of an infected file can be any of the following:

  • .cpl
  • .scr
  • .pif

MyDoom.AE worm can also send itself in a ZIP archive.

The worm can attach a fake anti-virus scanning report to the message it sends:

+++ Attachment: No Virus found    

where <av_vendor_string> string can be one of the following:

  • +++ MessageLabs AntiVirus - www.messagelabs.com
  • +++ Bitdefender AntiVirus - www.bitdefender.com
  • +++ MC-Afee AntiVirus - www.mcafee.com
  • +++ Kaspersky AntiVirus - www.kaspersky.com
  • +++ Panda AntiVirus - www.pandasoftware.com
  • +++ Norman AntiVirus - www.norman.com
  • +++ F-Secure AntiVirus - www.f-secure.com
  • +++ Norton AntiVirus - www.symantec.com

The worm fakes the sender's address. It uses the following list of names to compose the fake address:

  • Leon
  • Tom
  • Marcus
  • Troy
  • Walter
  • Eric
  • Matthew
  • Kenneth
  • Charles
  • Tommy
  • Jim
  • Francisco
  • Ricky
  • Dennis
  • Scott
  • Jason
  • George
  • Richard
  • Lloyd
  • Jay
  • Leroy
  • Carl
  • Jerry
  • Frank
  • Kevin
  • Donald
  • David
  • Bill
  • Oscar
  • Mario
  • Henry
  • Joshua
  • Jeffrey
  • Anthony
  • Mark
  • William
  • Ronnie
  • Miguel
  • Bernard
  • Douglas
  • Gregory
  • Larry
  • Ronald
  • Paul
  • Michael
  • Jon
  • Clifford
  • Alexander
  • Harold
  • Raymond
  • Jose
  • Brian
  • Daniel
  • Robert
  • Alex
  • Theodore
  • Barry
  • Peter
  • Andrew
  • Timothy
  • Edward
  • Thomas
  • John
  • Calvin
  • Micheal
  • Randall
  • Patrick
  • Stephen
  • Gary
  • Steven
  • JosephJames

The worm uses the following list of domain names to compose the fake sender's address:

  • @microsoft.com
  • @symantec.com

Backdoor component

Upon installation the worm drops a file named 'TCP5424.dll' to Windows System folder. The following startup key is created in the Registry:

  • [HKCR\CLSID\{E6FB5E20-DE35-11CF-9C87-00AA005127ED}\InprocServer32] @ = "%WinSysDir%\tcp5424.dll"

where "%WinSysDir%" represents Windows System directory. This DLL file is a backdoor that listens on TCP port 5424 for remote commands. The backdoor allows to upload and activate files on an infected computer.

Payload

The worm modifies the HOSTS file to block access to the following websites:

  • www.pandasoftware.com
  • www.symantec.com
  • securityresponse.symantec.com
  • symantec.com
  • www.sophos.com
  • sophos.com
  • www.mcafee.com
  • mcafee.com
  • liveupdate.symantecliveupdate.com
  • www.viruslist.com
  • viruslist.com
  • viruslist.com
  • f-secure.com
  • www.f-secure.com
  • kaspersky.com
  • www.avp.com
  • www.kaspersky.com
  • avp.com
  • www.networkassociates.com
  • networkassociates.com
  • www.ca.com
  • ca.com
  • mast.mcafee.com
  • my-etrust.com
  • www.my-etrust.com
  • download.mcafee.com
  • dispatch.mcafee.com
  • secure.nai.com
  • nai.com
  • www.nai.com
  • update.symantec.com
  • updates.symantec.com
  • us.mcafee.com
  • liveupdate.symantec.com
  • customer.symantec.com
  • rads.mcafee.com
  • trendmicro.com
  • www.trendmicro.com

Additionally the worm creates the following keys from the Registry:

  • [HKLM\Software\Microsoft\Windows\CurrentVersion\Run] "MsnMsgr" "ICQ Net"

The message to AV vendors

The worm contains a message to AV vendors in its body:

+++ Attachment: No Virus found

This message is extracted by the worm to Windows System folder as 'msg15.txt' file.

Date Created: -

Date Last Modified: -