Worm/Mydoom.BC - Worm

See also

Summary

Full description

Statistics

Virus:	Worm/Mydoom.BC
Date discovered:	01/03/2005
Type:	Worm
In the wild:	Yes
Reported Infections:	Low
Distribution Potential:	Low to medium
Damage Potential:	Medium
Static file:	Yes
File size:	48.766 Bytes
MD5 checksum:	27ab71805c9fa8447c787e50843eceb5
IVDF version:	6.30.00.6 - Tue, 01 Mar 2005 15:34 (GMT+1)

General Method of propagation:
   • Email

Aliases:
   • Mcafee: W32/Mytob.gen
   • Sophos: W32/Mytob-C
   • Panda: W32/Mytob.C.worm
   • Eset: Win32/Mytob.D
   • Bitdefender: Worm.Generic.82094

Platforms / OS:
   • Windows 2000
   • Windows XP
   • Windows 2003

Side effects:
   • Drops malicious files
   • Registry modification
   • Third party control

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

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

– [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices]
   • "LSA"="wfdmgr.exe"

To each registry key one of the values is added in order to run the processes after reboot:

– [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   • "LSA"="wfdmgr.exe"

– [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   • "LSA"="wfdmgr.exe"

The following registry keys are added:

– [HKCU\SYSTEM\CurrentControlSet\Control\Lsa]
   • "LSA"="wfdmgr.exe"

– [HKCU\Software\Microsoft\OLE]
   • "LSA"="wfdmgr.exe"

The following registry keys are changed:

– [HKLM\SOFTWARE\Microsoft\Ole]
   New value:
   • "LSA"="wfdmgr.exe"

– [HKLM\SYSTEM\CurrentControlSet\Control\Lsa]
   New value:
   • "LSA"="wfdmgr.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:
It uses the Messaging Application Programming Interface (MAPI) in order to send emails. The characteristics are further described:

From:
The sender address is spoofed.
The sender address is the user's Outlook account.

To:
– Email addresses found in specific files on the system.
– Email addresses gathered from WAB (Windows Address Book)
– Generated addresses

Body:
The body of the email is one of the lines:
   • Mail transaction failed. Partial message is available.
   • The message contains Unicode characters and has been sent as a binary attachment.
   • The message cannot be represented in 7-bit ASCII encoding and has been sent as a binary attachment.

Attachment:
The filenames of the attachments is constructed out of the following:

– It starts with one of the following:
   • body
   • message
   • test
   • data
   • file
   • text
   • doc
   • readme
   • document

    Continued by one of the following fake extensions:
   • bat
   • cmd
   • exe
   • scr
   • pif

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

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; jack; bill; stan; smith; steve;
      matt; dave; dan; joe; jane; bob; robert; peter; tom; ray; mary; serg;
      brian; jim; maria; leo; jose; andrew; sam; george; david; kevin; mike;
      james; michael; alex; john; accoun; certific; listserv; ntivi;
      support; icrosoft; admin; page; the.bat; gold-certs; ca; feste;
      submit; not; help; service; privacy; somebody; no; soft; contact;
      site; rating; bugs; me; you; your; someone; anyone; nothing; nobody;
      noone; webmaster; postmaster; samples; info; root

It combines the result with domains that were found in files, which were previously searched for addresses.

MX Server:
It has the ability to contact one of the following MX servers:
   • gate
   • ns
   • relay
   • mail1
   • mxs
   • mx1
   • smtp
   • mail
   • mx

Network Infection In order to ensure its propagation the malware attemps to connect to other machines as described below.

Exploit:
It makes use of the following Exploit:
– MS04-011 (LSASS Vulnerability)

IP address generation:
It creates random IP addresses while it keeps the first octet from its own address. Afterwards it tries to establish a connection with the created addresses.

IRC To deliver system information and to provide remote control it connects to the following IRC Server:

Server: irc.bl**********.net
Port: 6667
Channel: #d3
Nickname: %random character string%

– Furthermore it has the ability to perform actions such as:
    • Execute file
    • Perform network scan
    • Updates itself

Backdoor on a random TCP port in order to provide an FTP server.

File details Runtime packer:
In order to aggravate detection and reduce size of the file it is packed with a runtime packer.

See a brief description here.

Description inserted by Petre Galan on Fri, 05 Mar 2010 13:29 (GMT+1)
Description updated by Petre Galan on Fri, 05 Mar 2010 13:57 (GMT+1)

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