Worm/Mytob.KF - Worm

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Summary

Full description

Statistics

Virus:	Worm/Mytob.KF
Date discovered:	06/10/2005
Type:	Worm
In the wild:	Yes
Reported Infections:	Low
Distribution Potential:	Medium
Damage Potential:	Medium
Static file:	Yes
File size:	37.888 Bytes
MD5 checksum:	521040e494799b8065712d677d980785
VDF version:	6.32.00.65 - Thu, 06 Oct 2005 17:00 (GMT+1)

General Method of propagation:
   • Email

Aliases:
   • Kaspersky: Email-Worm.Win32.Fanbot.d
   • TrendMicro: WORM_MYTOB.KY
   • Sophos: W32/Sdbot-Fam
   • Grisoft: I-Worm/Mytob.MC
   • Eset: Win32/Mytob.KT
   • Bitdefender: Backdoor.PlunixHell.A

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

Side effects:
   • Blocks access to security websites
   • Registry modification
   • Steals information
   • Third party control

Right after execution the following information is displayed:

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

It deletes the initially executed copy of itself.

The following file is created:

– C:\Shell.sys This file contains collected keystrokes.

Registry The following registry key is changed:

– HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
   Old value:
   • "Shell"=%user defined settings%
     "Userinit"=%user defined settings%
   New value:
   • "Shell"="Explorer.exe Phantom.exe"
     "Userinit"="userinit.exe,Phantom.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:

From:
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.

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

Subject:
One of the following:
   • Notice of account limitation
   • Email Account Suspension
   • Security measures
   • Members Support
   • Important Notification
   • Warning Message: Your services near to be closed.
   • Your Account is Suspended For Security Reasons
   • *DETECTED* Online User Violation
   • Your Account is Suspended
   • Your new account password is approved
   • You have successfully updated your password
   • Your password has been successfully updated
   • Your password has been updated

Body:
The body of the email is one of the following:

   • Dear %receiver's domain name from email address% Member,
     We have temporarily suspended your email account %receiver's email address%
     This might be due to either of the following reasons:
     1. A recent change in your personal information (i.e. change of address).
     2. Submiting invalid information during the initial sign up process.
     3. An innability to accurately verify your selected option of subscription due to an internal error within our processors.
     See the details to reactivate your %receiver's domain name from email address% account.
     Sincerely,The %sender's domain name from email address% Support Team

     +++ Attachment: No Virus (Clean)
     +++ %sender's domain name from email address% Antivirus - www.%sender's domain name from email address%

   • Dear user %username from receiver's email address% ,
     You have successfully updated the password of your %receiver's domain name from email address% account.
     If you did not authorize this change or if you need assistance with your account, please contact %sender's domain name from email address% customer service at: %sender's email address%
     Thank you for using%sender's domain name from email address%!
     The %sender's domain name from email address% Support Team

     +++ Attachment: No Virus (Clean)
     +++ %sender's domain name from email address% Antivirus - www.%sender's domain name from email address%

   • Dear%receiver's domain name from email address% Member,
     Your e-mail account was used to send a huge amount of unsolicited spam messages during the recent week. If you could please take 5-10 minutes out of your online experience and confirm the attached document so you will not run into any future problems with the online service.

     If you choose to ignore our request, you leave us no choice but to cancel your membership.
     Virtually yours,
     The %sender's domain name from email address% Support Team

     +++ Attachment: No Virus found
     +++%sender's domain name from email address% Antivirus - www.%sender's domain name from email address%

   • Dear user %username from receiver's email address% ,
     It has come to our attention that your %sender's domain name from email address% User Profile ( x ) records are out of date. For further details see the attached document.
     Thank you for using %sender's domain name from email address% !
     The %sender's domain name from email address% Support Team

     +++ Attachment: No Virus (Clean)
     +++ %sender's domain name from email address% Antivirus - www.%sender's domain name from email address%

Attachment:
The filename of the attachment is one of the following:
   • accepted-password.zip
   • account-details.zip
   • account-info.zip
   • account-password.zip
   • account-report.zip
   • approved-password.zip
   • document.zip
   • email-details.zip
   • email-password.zip
   • important-details.zip
   • new-password.zip
   • password.zip
   • readme.zip
   • updated-password.zip

The attachment is an archive containing a copy of the malware itself.

The email looks like the following:

Mailing Search addresses:
It searches the following files for email addresses:
   • adb; asp; cfg; cgi; dbx; ht; htm; html; jsp; mdb; msg; php; sht; tbb;
      txt; vbe; vbs; xml

Address generation for TO field:
To generate addresses it uses the following strings:
   • adam; alex; andrew; anna; bill; bob; brenda; brent; brian; claudia;
      dan; dave; david; debby; frank; fred; george; helen; jack; james;
      jane; jerry; jim; jimmy; joe; john; jose; josh; julie; kevin; leo;
      linda; maria; mary; matt; michael; mike; paul; peter; ray; robert;
      sales; sam; sandra; serg; smith; stan; steve; ted; tom

Address generation for FROM field:
To generate addresses it uses the following strings:
   • noreply
   • webmaster
   • register
   • info
   • admin
   • service
   • mail
   • administrator
   • support

Avoid addresses:
It does not send emails to addresses containing one of the following strings:
   • -._!; -._!@; .edu; .gov; .mil; abuse; accoun; acketst; admin; ahn;
      antivi; anyone; arin.; avp; be_loyal:; berkeley; borlan; bsd; bugs;
      certific; contact; duba; example; fbi; fcnz; feste; fido; foo.; f-pro;
      freeav; f-secur; fsf.; gnu; gold-certs; google; gov.; help; hotmail;
      iana; ibm.com; icrosof; icrosoft; ietf; info; inpris; isc.o; isi.e;
      jiangmin; kaspersky; kernel; linux; listserv; master; math; mcafee;
      messagelabs; mit.e; mozilla; msn.; mydomai; nobody; nodomai; noone;
      norman; norton; not; nothing; ntivi; page; panda; pgp; postmaster;
      privacy; rating; rfc-ed; ripe.; rising; root; ruslis; samples; sdbot;
      secur; sendmail; service; site; slashdot; soft; somebody; someone;
      sopho; sourceforge; spm; submit; support; syma; symantec; tanford.e;
      the.bat; unix; usenet; utgers.ed; viruslis; webmaster; www; you; your

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.

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

Server: Small**********.3322.org
Port: 5263
Channel: #xiaoyu
Nickname: %five-digit random character string%

– This malware has the ability to collect and send information such as:
    • CPU speed
    • Current user
    • Free disk space
    • Free memory
    • Information about the network
    • Size of memory
    • System directory
    • Username
    • Information about the Windows operating system

– Furthermore it has the ability to perform actions such as:
    • Launch DDoS ICMP flood
    • Launch DDoS SYN flood
    • Launch DDoS UDP flood
    • Download file
    • Execute file
    • Kill process
    • Open remote shell
    • Restart system
    • Send emails
    • Start spreading routine
    • Terminate process
    • Updates itself
    • Upload file
    • Visit a website

Hosts The host file is modified as explained:

– In this case existing entries are deleted.

– Access to the following domains is effectively blocked:
   • jiangmin.com; www.jiangmin.com; Update2.JiangMin.com;
      Update3.JiangMin.com; rising.com.cn; www.rising.com.cn;
      online.rising.com.cn; iduba.net; www.iduba.net; kingsoft.com;
      db.kingsoft.com; scan.kingsoft.com; kaspersky.com.cn;
      www.kaspersky.com.cn; symantec.com.cn; www.symantec.com.cn;
      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;
      kaspersky-labs.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.pandaguard.com; pandasoftware.com;
      www.pandasoftware.com; www.trendmicro.com; www.grisoft.com;
      www.microsoft.com; microsoft.com; www.virustotal.com; virustotal.com;
      www.amazon.com; www.amazon.co.uk; www.amazon.ca; www.amazon.fr;
      www.paypal.com; paypal.com; moneybookers.com; www.moneybookers.com;
      www.ebay.com; ebay.com

The modified host file will look like this:

Miscellaneous Mutex:
It creates the following Mutex:
   • [Phantom]

String:
Furthermore it contains the following strings:
   • Play with The best Die like the rest.
   • HellBot3 have BackDoor in HellMsn.h. The HellBot3 author is an idiocy!!!
   • [Phantom] 2005 Made By Evil[xiaou]. Greetz to good friend x140d4n. Based On sdbot&&mydoom.

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 Irina Boldea on Fri, 20 Jan 2006 16:28 (GMT+1)
Description updated by Irina Boldea on Fri, 20 Jan 2006 17:30 (GMT+1)

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