WORM_MYTOB.PX

Malware type: Worm

Aliases: Net-Worm.Win32.Kidala.a (Kaspersky), W32/Mytob.gen@MM (McAfee), W32.Mytob@mm (Symantec), Worm/Kidala.A (Avira), W32/Mytob-HP (Sophos),

In the wild: Yes

Destructive: No

Language: English

Platform: Windows 98, ME, NT, 2000, XP, Server 2003

Encrypted: No

Overall risk rating:

Reported infections:

Damage potential:

High

Distribution potential:

High

Infection Channel 1 : Propagates via email


Infection Channel 2 : Propagates via network shares


Infection Channel 3 : Propagates via instant messaging applications


Infection Channel 4 : Propagates via peer-to-peer networks


Infection Channel 5 : Propagates via IRC


Infection Channel 6 : Propagates via software vulnerabilities


Description: 

To get a one-glance comprehensive view of the behavior of this worm, refer to the Behavior Diagram shown below.

WORM_MYTOB.PX Behavior Diagram

Malware Overview

This worm is able spread quickly to many systems due to multiple propagation techniques at its disposal.

This worm propagates by attaching copies of itself to email messages that it sends to target addresses, using its own Simple Mail Transfer Protocol (SMTP) engine. It is capable of sending email messages without using mailing applications, such as Microsoft Outlook. Click here to view the details of the email messages it sends out.

It gathers target email addresses from the Windows Address Book (WAB). It also creates email addresses using common names appended with a domain name.

This worm spreads through network shares as well. It searches for certain shares, where it drops a copy of itself. It uses a list of user names and passwords to gain access to password-protected shares.

It takes advantage of the following Windows vulnerabilities to propagate across networks:

  • WebDAV vulnerability
  • Windows RPC DCOM vulnerability
  • Windows LSASS vulnerability

The mentioned vulnerabilities are discussed in detail on the following Web pages:

Moreover, it also takes advantage of the DameWare Remote Control Server Stack Overflow Exploit vulnerability.

As another propagation technique, it also drops copies of itself to folders related to popular peer-to-peer (P2P) file-sharing applications, as well as to folders it assumes as shared. It uses interesting file names for the said copies, enticing target users to download this worm's copy onto their system. The said routine thus allows this worm to propagate via P2P file-sharing applications.

It also propagates via chat, both through Internet Relay Chat (IRC) and Instant Messenger. It sends messages containing a link to a URL where a copy of this worm can be downloaded to target users.

It is capable of terminating several processes related to antivirus and security applications. The said routine makes the detection, and consequent termination of this worm more difficult.

Furthermore, it has backdoor capabilities. It opens a random port, which allows a remote user to perform malicious commands on the affected machine, thus compromising system security.

For additional information about this threat, see:

Description created: Apr. 18, 2006 11:40:52 AM GMT -0800


TECHNICAL DETAILS


File type: PE

Memory resident:  Yes

Size of malware: 131,800 Bytes

Ports used: Random

Initial samples received on: Apr 18, 2006

Vulnerability used:  (MS04-011) Security Update for Microsoft Windows (835732), (MS03-007) Unchecked Buffer In Windows Component Could Cause Server Compromise (815021), (MS03-026) Buffer Overrun In RPC Interface Could Allow Code Execution, DameWare Mini Remote Control Server Stack Overflow Exploit

Payload 1: Compromises system security

Payload 2: Terminates processes

Details:

Installation and Autostart Technique

Upon execution, this worm drops a copy of itself as MICROUPDATE.EXE in the Windows system folder. It then creates the following registry entry to ensure its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Microupdate = "%System%\MICROUPDATE.EXE"

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It creates the following registry key as part of its installation routine:

HKEY_CURRENT_USER\Software\Obsidium\
{FD7C1D34-48788261-D2586D31-13A8DB8B}

It also drops a copy of itself to WinRAR archives that are not password-protected. It uses the file name {Random}.COM. This method allows itself to be easily downloaded in peer-to-peer file-sharing networks.

Propagation via Email

This worm propagates by attaching copies of itself to email messages that it sends to target addresses, using its own Simple Mail Transfer Protocol (SMTP) engine. It is capable of sending email messages without using mailing applications, such as Microsoft Outlook.

The email it sends out has the following details:

Subject: (any of the following)
• {Blank}
• {Random}
• error
• hello
• hi
• mail delivery system
• mail transaction failed
• server error
• server report
• status
• test

Message Body: (any of the following)
• {Random}
• {Blank}
• Mail Transaction failed. Partial Message is available.
• The message contains Unicode characters and has been sent as binary attachment.
• The message cannot be represented in 7-bit ASCII and has been sent as a binary attachment.

Attachment: (any of the following)
• data
• doc
• document
• file
• message
• readme
• text

With any of the following primary extensions:
• .bat
• .cmd
• .exe
• .pif
• .scr
• .txt
• .htm
• .doc

With any of the following secondary extensions:
• .bat
• .cmd
• .exe
• .pif
• .scr

The said attachment may also arrive as is, or archived as a .ZIP file. For example, an attachment name may be file.bat.txt, or file.bat.txt.zip.

It gathers target email addresses from the Windows Address Book (WAB). It may also generate email addresses by using any of the following names appended with a domain name, which it copies from the previously harvested email addresses:

  • alice
  • andrew
  • brenda
  • brent
  • brian
  • claudia
  • david
  • debby
  • george
  • helen
  • james
  • jerry
  • jimmy
  • julie
  • kevin
  • linda
  • maria
  • michael
  • peter
  • robert
  • sandra
  • smith
  • steve

The following are the domain names it appends to the mentioned user names:

  • aol.com
  • ayna.com
  • hotmail.com
  • maktoob.com
  • microsoft.com
  • msn.com
  • usa.com
  • usa.net
  • yahoo.com

It checks the following registry key to search for available SMTP servers to use in sending more emails:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Account Manager\Accounts

If it does not find a default mail server, it queries the message exchange servers of the gathered email addresses by appending the domain names of the said addresses with the following strings:

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

It avoids email addresses containing any of the following substrings:

  • abuse
  • accoun
  • acketst
  • admin
  • anyone
  • arin.
  • be_loyal:
  • berkeley
  • borlan
  • certific
  • contact
  • example
  • feste
  • gold-certs
  • google
  • hotmail
  • ibm.com
  • icrosof
  • icrosoft
  • inpris
  • isc.o
  • isi.e
  • kernel
  • linux
  • listserv
  • mit.e
  • mozilla
  • mydomai
  • nobody
  • nodomai
  • noone
  • nothing
  • ntivi
  • panda
  • postmaster
  • privacy
  • rating
  • rfc-ed
  • ripe.
  • ruslis
  • samples
  • secur
  • sendmail
  • service
  • somebody
  • someone
  • sopho
  • submit
  • support
  • tanford.e
  • the.bat
  • usenet
  • utgers.ed
  • webmaster

Propagation via Network Shares and Software Vulnerabilities

This worm spreads through network shares. It searches for the default share IPC$, where it drops a copy of itself.

It uses the following user names and passwords to gain access to password-protected shares:

  • 12345
  • 123456
  • 1234567
  • 12345678
  • 123456789
  • 1234567890
  • 12345678910
  • access
  • accounting
  • accounts
  • admin
  • Administrador
  • administrat
  • Administrateur
  • administrator
  • Admins
  • backup
  • bitch
  • blank
  • brian
  • changeme
  • chris
  • cisco
  • compaq
  • computer
  • control
  • database
  • databasepass
  • databasepassword
  • db1234
  • dbpass
  • dbpassword
  • default
  • domain
  • domainpass
  • domainpassword
  • exchange
  • george
  • guest
  • hello
  • homeuser
  • internet
  • intranet
  • katie
  • linux
  • login
  • loginpass
  • network
  • nokia
  • oeminstall
  • oemuser
  • office
  • Oracle
  • orainstall
  • outlook
  • owner
  • ownerstaff
  • pass1234
  • passwd
  • password
  • password1
  • peter
  • qwerty
  • server
  • siemens
  • sqlpassoainstall
  • Staff
  • student
  • susan
  • system
  • Teacher
  • technical
  • win2000
  • win2k
  • win98
  • windows
  • winnt
  • winpass
  • winxp
  • wwwadmin

It also takes advantage of the following Windows vulnerabilities to propagate across networks:

  • WebDAV vulnerability
  • Windows RPC DCOM vulnerability
  • Windows LSASS vulnerability

The mentioned vulnerabilities are discussed in detail on the following Web pages:

Moreover, it also takes advantage of the DameWare Remote Control Server Stack Overflow Exploit vulnerability.

Propagation via Peer-to-peer File-sharing Applications

This worm searches the affected system for the existence of any the following folders, which are mostly related to popular P2P file-sharing applications:

  • C:\my downloads
  • C:\Program Files\eDonkey2000\Incoming
  • C:\Program Files\Files\Kazaa Lite\My Shared Folder
  • C:\Program files\kazaa\my shared folder
  • C:\Program Files\LimeWire\Shared
  • C:\Program Files\Morpheus\My Shared Folder

It also searches for any folder with the string, My Shared Folder.

This worm drops the following copies of itself using various file names in different P2P applications:

In Warez P2P:
  • Britney_Spears_sucks_someones_dick.scr
  • Madonna_the_most_sexiest_girl_in_the_world.com
  • Mariah_Carey_showering_in_bathroom.com
  • nice_big_asshole_fuck_Jennifer_Lopez.scr
In Limewire:
  • Alcohol_120%_patch
  • DarkAngel_Lady_get_fucked_so_hardly
  • LimeWire_speed%20%20
  • Outlook_hotmail%20_fix
In eDonkey:
  • Angilina_Jolie_Sucks_a_Dick
  • BritneySpears_SoSexy
  • DAP7.4.x.x_crack
  • JenniferLopez_Film_Sexy_Enough
  • NortonAV2006_Crack
In iMesh:
  • KAV2006_Crack
  • MSN7.0Loader
  • MSN7.0UniversalPatch
  • YahooMessenger_Loader
  • ZoneAlarmPro6.xx_Crack
In Morpheus:
  • lcc-wiz_update
  • notepad%20%20
  • Opera8
  • RealPlayer10.xx_crack
  • TaskCatcher
In KaZaa:
  • activation_crack
  • dcom_patch
  • icq2006-final
  • nuke2006
  • office_crack
  • rootkitXP
  • strip-girl-3.0
  • winamp6

It uses any of the following extensions for the aforementioned file names:

  • BAT
  • EXE
  • PIF
  • SCR

Propagation via Internet Relay Chat and Instant Messenger

This worm propagates via Internet Relay Chat (IRC). It creates an IRC script file that automatically sends a message to users who joined a specific IRC channel. The said message contains a link that when clicked, downloads this worm onto the recipient's machine. The IRC message it sends has the following details:

{Nickname} just look at this brother http://{Sender's IP address}:2001/Hot.pif

Furthermore, this worm propagates via instant messengers. It checks any active instant messaging (IM) application in the affected system by searching for open IM windows. Once found, this worm uses the said window to send a message to target recipients. The message may be any of the following:

  • hehe,watch this http://{Sender's IP address}:2001/{Random file name}
  • LOL this shit is funny http://{Sender's IP address}:2001/{Random file name}
  • lol, don't forget to watch this video http://{Sender's IP address}:2001/{Random file name}
  • look at this video http://{Sender's IP address}:2001/{Random file name}
  • your going to like this :D http://{Sender's IP address}:2001/{Random file name}

This worm may use any of the following file names to include in the link it sends:

  • crazy5.scr
  • crazyjump.scr
  • exposed.scr
  • funny2.scr
  • funny3.scr
  • haha.scr
  • lucky.scr
  • mjackson.scr
  • picture1.scr

On both propagation methods, this worm opens port 2001 to allow HTTP access on the affected computer. Once the link is clicked, it downloads a copy of itself using the said port.

Backdoor Capabilities

This worm acts as a server program controlled by an Internet Relay Chat (IRC) bot. It opens a random port and connects to a certain IRC server. It then joins an IRC channel. Once connected, this server program receives commands from the IRC bot. The said commands are used to control the target system and the behavior of the server program. The following are some examples of the commands it executes:

  • Download and execute files
  • Remove, terminate, or update itself
  • Perform denial of service (DoS) attacks

Process Termination

This worm terminates the following processes, most of which are related to security and antivirus applications:

  • _AVPCC.EXE
  • _AVPM.EXE
  • _FINDVIRU.EXE
  • ACKWIN32.EXE
  • ALOGSERV.EXE
  • AMON.EXE
  • ANTI-TROJAN.EXE
  • APVXDWIN.EXE
  • ATGUARD.EXE
  • AVE32.EXE
  • AVKSERV.EXE
  • AVNT.EXE
  • AVPCC.EXE
  • AVPM.EXE
  • AVWIN95.EXE
  • BLACKICE.EXE
  • CLAW95CF.EXE
  • CMGRDIAN.EXE
  • ECENGINE.EXE
  • ESAFE.EXE
  • F-PROT95.EXE
  • FINDVIRU.EXE
  • FP-WIN.EXE
  • FPROT.EXE
  • GUARDDOG.EXE
  • IAMAPP.EXE
  • IOMON98.EXE
  • KAVPF.EXE
  • LOOKOUT.EXE
  • NAVAPSVC.EXE
  • NAVAPW32.EXE
  • NAVNT.EXE
  • NAVW32.EXE
  • NAVWNT.EXE
  • NOD32.EXE
  • NSPLUGIN.EXE
  • OGRC.EXE
  • OUTPOST.EXE
  • OUTPOSTINSTALL.EXE
  • OUTPOSTPROINSTALL.EXE
  • RAV7.EXE
  • RULAUNCH.EXE
  • SCAN32.EXE
  • SPIDER.EXE
  • VET95.EXE
  • VETTRAY.EXE
  • VSMAIN.EXE
  • ZAPRO.EXE
  • ZAPSETUP3001.EXE
  • ZATUTOR.EXE
  • ZONALARM.EXE
  • ZONALM2601.EXE
  • ZONEALARM.EXE

Affected Platforms

This worm runs on Windows 98, ME, NT, 2000, XP, and Server 2003.

Analysis By: Marilyn Calangian Dolormente

Revision History:

First pattern file version: 5.480.05
First pattern file release date: Aug 15, 2008

SOLUTION


Minimum scan engine version needed: 7.500

Pattern file needed: 6.695.00

Pattern release date: Dec 15, 2009


Important note: The "Minimum scan engine" refers to the earliest Trend Micro scan engine version guaranteed to detect this threat. However, Trend Micro strongly recommends that you update to the latest version in order to get comprehensive protection. Download the latest scan engine here.

Solution:

Terminating the Malware Program

This procedure terminates the running malware process.

  1. Open Windows Task Manager.
    • On Windows 98 and ME, press
    CTRL%20ALT%20DELETE
    • On Windows NT, 2000, XP, and Server 2003, press
    CTRL%20SHIFT%20ESC, then click the Processes tab.
  2. In the list of running programs*, locate the process:
    MICROUPDATE.EXE
  3. Select the malware process, then press either the End Task or the End Process button, depending on the version of Windows on your computer.
  4. To check if the malware process has been terminated, close Task Manager, and then open it again.
  5. Close Task Manager.

*NOTE: On computers running Windows 98 and ME, Windows Task Manager may not show certain processes. You can use a third party process viewer such as Process Explorer to terminate the malware process.

On computers running all Windows platforms, if the process you are looking for is not in the list displayed by Task Manager or Process Explorer, continue with the next solution procedure, noting additional instructions. If the malware process is in the list displayed by either Task Manager or Process Explorer, but you are unable to terminate it, restart your computer in safe mode.

Editing the Registry

This malware modifies the computer's registry. Users affected by this malware may need to modify or delete specific registry keys or entries. For detailed information regarding registry editing, please refer to the following articles from Microsoft:

  1. HOW TO: Backup, Edit, and Restore the Registry in Windows 95, Windows 98, and Windows ME
  2. HOW TO: Backup, Edit, and Restore the Registry in Windows NT 4.0
  3. HOW TO: Backup, Edit, and Restore the Registry in Windows 2000
  4. HOW TO: Back Up, Edit, and Restore the Registry in Windows XP and Server 2003

Removing Autostart Entries from the Registry

Removing autostart entries from the registry prevents the malware from executing at startup.

If the registry entries below are not found, the malware may not have executed as of detection. If so, proceed to the succeeding solution set.

  1. Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
  2. In the left panel, double-click the following:
    HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>
    Windows>CurrentVersion>Run
  3. In the right panel, locate and delete the entry:
    Microupdate = "%System%\MICROUPDATE.EXE"
    (Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, and C:\Windows\System32 on Windows XP and Server 2003.)

Removing Other Malware Entry from the Registry

  1. Still in Registry Editor, in the left panel, double-click the following:
    HKEY_CURRENT_USER>Software>Obsidium
  2. In the left panel, locate and delete the key:
    {FD7C1D34-48788261-D2586D31-13A8DB8B}
  3. Close Registry Editor.

Important Windows ME/XP Cleaning Instructions

Users running Windows ME and XP must disable System Restore to allow full scanning of infected computers.

Users running other Windows versions can proceed with the succeeding solution set(s).

Running Trend Micro Antivirus

If you are currently running in safe mode, please restart your computer normally before performing the following solution.

Scan your computer with Trend Micro antivirus and delete files detected as WORM_MYTOB.PX. To do this, Trend Micro customers must download the latest virus pattern file and scan their computer. Other Internet users can use HouseCall, the Trend Micro online virus scanner.

Applying Patches

This malware exploits known vulnerabilities in Windows and Dameware. Download and install the following fix patches supplied by respective vendors:

(*Note: Microsoft Security Bulletin MS03-039 contains the updated patch for Microsoft Security Bulletin MS03-026.)

Refrain from using this product until the appropriate patch has been installed. Trend Micro advises users to download critical patches upon release by vendors.




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