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  3. W32.Mydoom.M@mm

W32.Mydoom.M@mm

Risk Level 2: Low

Discovered:
July 26, 2004
Updated:
February 13, 2007 12:25:43 PM
Also Known As:
W32/Mydoom.o@MM [McAfee], W32/MyDoom-O [Sophos], WORM_MYDOOM.M [Trend Micro], Win32.Mydoom.O [Computer Assoc, I-Worm.Mydoom.m [Kaspersky], W32/Mydoom.N.worm [Panda]
Type:
Worm
Systems Affected:
Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows XP

When W32.Mydoom.M@mm is executed, it performs the following actions:
  1. Creates the following registry keys, which mark the computer as infected:
    • HKEY_LOCAL_MACHINE\Software\Microsoft\Daemon
    • HKEY_CURRENT_USER\Software\Microsoft\Daemon

  2. Copies itself as %Windir%\java.exe.

    Note: %Windir% is a variable. The worm locates the Windows installation folder (by default, this is C:\Windows or C:\Winnt) and copies itself to that location.

  3. Drops and executes %Windir%\services.exe, which is detected as Backdoor.Zincite.A. When executed, this file opens TCP port 1034 and listens for remote connections. The backdoor will also probe random IP addresses on port 1034 looking for other infected hosts.

  4. Adds the values:

    "Services" = "%Windir%\services.exe"
    "JavaVM" = "%Windir%\java.exe"


    to the registry key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

    so that the worm and backdoor load when Windows starts.

  5. May create the following files for logging purposes:
    • %Temp%\zincite.log
    • %Temp%\<randomly named file>.log

  6. Gathers email addresses from files with the following extensions:
    • .adb
    • .asp
    • .dbx
    • .ht*
    • .php
    • .pl
    • .sht
    • .tbb
    • .tx*
    • .wab

  7. Queries the following search engines to harvest additional email addresses for possible distribution:
    • search.lycos.com
    • search.yahoo.com
    • www.altavista.com
    • www.google.com

  8. When the worm finds an open Outlook window, it will attempt to send itself to the email addresses that it found.

    The email has the following characteristics:

    From:
    The From address will be spoofed.

    Subject: (One of the following)
    • hello
    • error
    • status
    • test
    • report
    • delivery failed
    • Message could not be delivered
    • Mail System Error - Returned Mail
    • Delivery reports about your e-mail
    • Returned mail: see transcript for details
    • Returned mail: Data format error

      Body:
      The content contained in the body of the email will vary, based on a number of text options. One of each of the phrases or words in brackets, separated by a "|", will appear:
    • Dear user {<recipient's email address>|of <recipient's email domain>},{ {{M|m}ail {system|server} administrator|administration} of <recipient's email domain> would like to {inform you{ that{:|,}|}|let you know {that|the following}{.|:|,}}|||||}
      {We have {detected|found|received reports} that y|Y}our {e{-|}mail |}account {has been|was} used to send a {large|huge} amount of {{unsolicited{ commercial|}|junk} e{-|}mail|spam}{ messages|} during {this|the {last|recent}} week.
      {We suspect that|Probably,|Most likely|Obviously,} your computer {had been|was} {compromised|infected{ by a recent v{iru}s|}} and now {run|contain}s a {trojan{ed|}|hidden} proxy server.
      {Please|We recommend {that you|you to}} follow {our |the |}instruction{s|} {in the {attachment|attached {text |}file} |}in order to keep your computer safe.
      {{Virtually|Sincerely} yours|Best {wishe|regard}s|Have a nice day},
      {<recipient's email domain> {user |technical |}support team.|The <recipient's email domain> {support |}team.}

    • {The|This|Your} message was{ undeliverable| not delivered} due to the following reason{(s)|}:
      Your message {was not|could not be} delivered because the destination {computer|server} was
      {not |un}reachable within the allowed queue period. The amount of time
      a message is queued before it is returned depends on local configura-
      tion parameters.
      Most likely there is a network problem that prevented delivery, but
      it is also possible that the computer is turned off, or does not
      have a mail system running right now.

    • Your message {was not|could not be} delivered within <random number> days:
      {{{Mail s|S}erver}|Host} <host used to send the email>} is not responding.
      The following recipients {did|could} not receive this message:
      <<recipient's email address>>
      Please reply to postmaster@{<sender's email domain>|<recipient's email domain>}
      if you feel this message to be in error.
      The original message was received at [current time]{
      | }from {<sender's email domain> ]|{<host used to send the email>]|]}}
      ----- The following addresses had permanent fatal errors -----
      {<<recipient's email address>>|<recipient's email address>}
      {----- Transcript of {the ||}session follows -----
      ... while talking to {host |{mail |}server ||||}{<recipient's email domain>.|<host used to send the email>]}:
      {>>> MAIL F{rom|ROM}:[From address of mail]
      <<< 50$d {[From address of mail]... |}{Refused|{Access d|D}enied|{User|Domain|Address} {unknown|blacklisted}}|554 <<recipient's email address>>... {Mail quota exceeded|Message is too
      large}
      554 <<recipient's email address>>... Service unavailable|550 5.1.2 <<recipient's email address>>... Host unknown (Name server: host not found)|554 {5.0.0 |}Service unavailable; ] blocked using {relays.osirusoft.com|bl.spamcop.net}{, reason: Blocked|}
      Session aborted{, reason: lost connection|}|>>> RCPT To:<<recipient's email address>>
      <<< 550 {MAILBOX NOT FOUND|5.1.1 <<recipient's email address>>... {User unknown|Invalid recipient|Not known here}}|>>> DATA
      {<<< 400-aturner; %MAIL-E-OPENOUT, error opening !AS as output
      |}{<<< 400-aturner; -RMS-E-CRE, ACP file create failed
      |}{<<< 400-aturner; -SYSTEM-F-EXDISKQUOTA, disk quota exceeded
      |}<<< 400}|}
      The original message was included as attachment

    • {{The|Your} m|M}essage could not be delivered

      Notes:
    • <recipient's email address> is the email address of the person receiving the email.
    • <recipient's email domain> is the domain of the receiver's email. For instance, if the email address is john_doe@example.com, the domain is "example.com."
    • <sender's email domain> is the domain of the sender's email. For instance, if the email address is john_doe@example.com, the domain is "example.com."
    • <host used to send the email> is name of the email server used by the infected computer. The worm gathers this information from the infected computer's registry.


      Attachment:
      The worm may generate an file name from a domain name of an email address gathered from the computer. For instance, if the worm finds an address john_doe@example.com on the infected computer, the attachment name could contain example.com.

      The attachment name may also be one of the following:
    • readme
    • instruction
    • transcript
    • mail
    • letter
    • file
    • text
    • attachment
    • document
    • message

      with one of the following extensions:
    • .cmd
    • .bat
    • .com
    • .exe
    • .pif
    • .scr
    • .zip

      the attachment may have a second extension, which will be one of the following:
    • doc
    • txt
    • htm
    • html

      Notes:
    • Approximately 30% of the time, the attachment will be zipped. In these cases the attachment may be compressed several times over.
    • There is a 15% chance the worm will attach a small junk file to the mail instead of a copy of itself.


      The worm will not send itself to addresses that contain the following strings:
    • mailer-d
    • spam
    • abuse
    • master
    • sample
    • accou
    • privacycertific
    • bugs
    • listserv
    • submit
    • ntivi
    • support
    • admin
    • page
    • the.bat
    • gold-certs
    • feste
    • not
    • help
    • foo
    • soft
    • site
    • rating
    • you
    • your
    • someone
    • anyone
    • nothing
    • nobody
    • noone
    • info
    • winrar
    • winzip
    • rarsoft
    • sf.net
    • sourceforge
    • ripe.
    • arin.
    • google
    • gnu.
    • gmail
    • seclist
    • secur
    • bar.
    • foo.com
    • trend
    • update
    • uslis
    • domain
    • example
    • sophos
    • yahoo
    • spersk
    • panda
    • hotmail
    • msn.
    • msdn.
    • microsoft
    • sarc.
    • syma
    • avp
    Symantec Gateway Security 2.0 - 5400 Series
    Symantec Gateway Security 1.0 – 5300 Series
    • Antivirus component: An update for the Symantec Gateway Security AntiVirus engine to protect against the W32.MyDoom.M@mm worm is now available. Symantec Gateway Security 5000 Series users are advised to run LiveUpdate.
    • Full application inspection firewall component: By default, Symantec's full application inspection firewall technology protects against the W32.MyDoom.M@mm worm by blocking attackers from accessing the TCP port 1034 backdoor on infected systems. Administrators are urged to verify that their security policies have not been modified to allow TCP port 1034 inbound.
    • When configured through the Policy Wizard, the SMTP rule created on the security gateway will block infected systems from directly sending email to the Internet.
    • IDS/IPS - Due to the propagation method of this mass-mailing worm, which does not include automatic network propagation techniques or any exploitation of network based vulnerabilities, we will NOT be releasing an update at this time. We are, however, constantly monitoring the threat landscape to protect against the latest attacks.

    Symantec Enterprise Firewall 8.0
    By default, Symantec's full application inspection firewall technology protects against the W32.MyDoom.M@mm worm by blocking attackers from accessing the TCP port 1034 backdoor on infected systems. Administrators are urged to verify that their security policies have not been modified to allow TCP port 1034 inbound.

    When configured through the Policy Wizard, the SMTP rule created on the security gateway will block infected systems from directly sending email to the Internet.

    Symantec Enterprise Firewall 7.0.x
    Symantec VelociRaptor 1.5
    By default, Symantec's full application inspection firewall technology protects against the W32.MyDoom.M@mm worm by blocking attackers from accessing the TCP port 1034 backdoor on infected systems. Administrators are urged to verify that their security policies have not been modified to allow TCP port 1034 inbound.

    When configured through the SMTP Wizard using the default settings, the SMTP rule created on the security gateway will block infected systems from directly sending email to the Internet.

    Symantec Clientless VPN Gateway 4400 Series
    Symantec Clientless VPN Gateway v5.0 is not affected by this threat. To reduce risk of further propagation you should also include a rule that only allows mail access from authenticated remote users to your internal mail server.

    Symantec Gateway Security 300 Series
    By default, Symantec's stateful inspection firewall technology prevents an attacker from accessing the TCP port 1034 backdoor on infected systems. Administrators are urged to verify that their security policy has not been modified to allow TCP port 1034 inbound and to use the AVpe feature of the SGS 300 series to make sure all their AV clients are up-to-date with their virus definitions.

    Symantec Firewall/VPN 100/200 Series
    By default, Symantec's stateful inspection firewall technology prevents an attacker from accessing the TCP port 1034 backdoor on infected systems. Administrators are urged to verify that their security policy has not been modified to allow TCP port 1034 inbound.

    Symantec AntiVirus Corporate Edition
    Symantec AntiVirus Corporate Edition will detect this threat and quarantine the file prior to executing.

    Symantec Client Security
    Symantec Client Security, which includes integrated antivirus, firewall, and intrusion detection capabilities will detect this threat and quarantine the file prior to executing. Customers may be prompted to allow or block traffic to and from this port. The default (recommended) response is block.

    Symantec Manhunt
    Due to the propagation method of this mass-mailing worm, which does not include automatic network propagation techniques or any exploitation of network-based vulnerabilities, we will NOT be releasing an update at this time. We are, however, constantly monitoring the threat landscape to protect against the latest attacks.

    Managed Security Services
    Symantec MSS is actively working with our customers to reduce the impact of this latest MyDoom variant. Symantec MSS is able to leverage its firewall log analytics to identify compromised systems, even though IDS signatures do not exist for this variant at this point in time. Symantec MSS has informed its global customer base through postings to our Web Portal and are actively engaged with customers to minimize possible impact. At this point in time, Symantec MSS has seen limited customer impact based on this mass-mailing worm. As vendors release IDS signatures, Symantec will deploy them on an emergency basis, to insure the highest level of possible detection and protection for this worm.

    Symantec Mail Security for SMTP 4.0
    Symantec Mail Security 4.0 for Domino
    Symantec Mail Security 4.5 for Exchange
    Mass-Mailer Cleanup functionality enhances virus outbreak management by automatically deleting infected mass-mailer messages and their attachments during and after a mass-mailer outbreak. No heuristic anti-spam or content filtering scans are performed on mass-mailer infected messages, which frees critical system resources that are needed during an outbreak.

    Recommendations

    Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

    • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
    • Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
    • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
    • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
    • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
    • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
    • If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
    • Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
    • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
    • Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
    • Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
    • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
    • For further information on the terms used in this document, please refer to the Security Response glossary.
    Writeup By: John Canavan
    Summary| Technical Details| Removal

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