Virus:Worm/Mytob.JH
Date discovered:01/08/2005
Type:Worm
In the wild:Yes
Reported Infections:Low
Distribution Potential:Medium to high
Damage Potential:Medium
Static file:Yes
File size:83.489 Bytes
MD5 checksum:cf9d8ca63bda4ba74f33b96dcd6e929e
VDF version:6.31.01.40

 General Method of propagation:
   • Email
   • Local network


Aliases:
   •  Symantec: W32/Mytob.gen@MM
   •  Sophos: W32/Forbot-FG
   •  Grisoft: I-Worm/Mytob.LW
   •  VirusBuster: I-Worm.Mytob.KJ
   •  Eset: Win32/Mytob.IL


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


Side effects:
   • Uses its own Email engine
   • Registry modification
   • Makes use of software vulnerability
   • Third party control

 Files It copies itself to the following location:
   • %SYSDIR%\wrmana32.exe

 Registry The following registry keys are continuously in an infinite loop added in order to run the processes after reboot.

–  HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   • "Windows NetDDe"="wrmana32.exe"

–  HKCU\Software\Microsoft\Windows\CurrentVersion\RunOnce
   • "Windows NetDDe"="wrmana32.exe"

–  HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
   • "Windows NetDDe"="wrmana32.exe"

–  HKCU\Software\Microsoft\Windows\CurrentVersion\Run
   • "Windows NetDDe"="wrmana32.exe"

–  HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
   • "Windows NetDDe"="wrmana32.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
   • You are banned!!!
   • We have suspended your account
   • Members Support
   • Important Notification
   • Warning Message: Your services near to be closed.
   • Your Account is Suspended For Security Reasons
   • *DETECTED* Online User Violation
   • *WARNING* Your email account is suspended
   • Your Account is Suspended



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

   • 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

   • Some information about your %receiver's domain name from email address% account is attached.
     The %sender's domain name from email address% Support Team


Attachment:
The filename of the attachment is one of the following:
   • readme.zip
   • document.zip
   • account-report.zip
   • account-info.zip
   • email-details.zip
   • account-details.zip
   • important-details.zip
   • information.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:
   • wab; adb; tbb; dbx; php; sht; htm; html; xml; cgi; jsp; txt; tmp


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:
   • register
   • mail
   • administrator
   • service



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.

 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 Exploits:
– MS04-007 (ASN.1 Vulnerability)
– MS04-011 (LSASS Vulnerability)


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


Infection process:
Creates an FTP script on the compromised machine in order to download the malware to the remote location.

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

Server: mystery.m0r**********
Port: 6667
Channel: #forb0t
Nickname: elite-%seven-digit random character string%
Password: false



– This malware has the ability to collect and send information such as:
    • CPU speed
    • Current user
    • Details about drivers
    • Free disk space
    • Free memory
    • Information about the network
    • Information about running processes
    • Size of memory
    • 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
    • Disable network shares
    • Download file
    • Edit registry
    • Enable network shares
    • Execute file
    • Kill process
    • Perform DDoS attack
    • Perform network scan
    • Perform port redirection
    • Register a service
    • Restart system
    • Send emails
    • Updates itself

 Backdoor The following port is opened:

– %SYSDIR%\wrmana32.exe on a random TCP port in order to provide an FTP server.

 Stealing – It uses a network sniffer that checks for the following strings:
   • account=; email=; exp=; address=; CVV2=; ccv2=; cvv2=; card=; cctype=;
      ccnumber=; amex=; visa=; mastercard=; VISA=; pass=; login=; password=;
      passwd=; :.login; :!login; :.secure; :!advscan; :.advscan; :.ipscan;
      :!ident; :.ident

 File details Programming language:
 The malware program was written in MS Visual C++.


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

Description inserted by Irina Boldea on Tuesday, August 15, 2006
Description updated by Irina Boldea on Tuesday, August 15, 2006

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