Worm/Mytob.AD - Worm

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Summary

Full description

Statistics

Virus:	Worm/Mytob.AD
Date discovered:	15/11/2005
Type:	Worm
In the wild:	Yes
Reported Infections:	Low
Distribution Potential:	Medium to high
Damage Potential:	Medium
Static file:	Yes
File size:	49.152 Bytes
MD5 checksum:	057e1a0Ec4443f5eeb83d9e44777c56f
VDF version:	6.30.00.79 - Sun, 10 Apr 2005 13:41 (GMT+1)

General Methods of propagation:
   • Email
   • Local network

Aliases:
   • Mcafee: W32/Mytob.gen@MM
   • Kaspersky: Net-Worm.Win32.Mytob.u
   • TrendMicro: WORM_MYTOB.AC
   • Sophos: W32/MyDoom-AJ
   • Grisoft: I-Worm/Mytob.AA
   • VirusBuster: I-Worm.Mytob.AC
   • Bitdefender: Win32.Worm.Mytob.AC

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

Side effects:
   • Blocks access to security websites
   • Uses its own Email engine
   • Registry modification
   • Makes use of software vulnerability
   • Third party control

Files It copies itself to the following locations:
   • %SYSDIR%\rnathchk.exe
   • C:\pic.scr
   • C:\see_this!.pif
   • C:\my_picture.scr

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]
   • "RealPlayer Ath Check" = "rnathchk.exe"

– [HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   • "RealPlayer Ath Check" = "rnathchk.exe"

– [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices]
   • "RealPlayer Ath Check" = "rnathchk.exe"

The following registry keys are added:

– [HKCU\Software\Microsoft\OLE]
   • "RealPlayer Ath Check" = "rnathchk.exe"

– [HKCU\SYSTEM\CurrentControlSet\Control\Lsa]
   • "RealPlayer Ath Check" = "rnathchk.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:
   • Error
   • Good day
   • hello
   • Mail Delivery System
   • MAIL TRANSACTION FAILED
   • SERVER REPORT
   • Status

Furthermore the subject line could contain random letters.

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

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

– Random string
   • data
   • doc
   • document
   • file
   • message
   • body
   • readme
   • test
   • text
   • %random character string%

    The file extension is one of the following:
   • BAT
   • CMD
   • EXE
   • PIF
   • SCR
   • ZIP

The attachment is 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
   • asp
   • php
   • sht
   • htm

Address generation for FROM field:
To generate addresses it uses the following strings:
   • sandra; lolita; britney; bush; linda; julie; jimmy; jerry; helen;
      debby; claudia; brenda; anna; madmax; 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

It combines this with domains from the following list or from addresses found in files on the system

The domain is one of the following:
   • aol.com
   • cia.gov
   • fbi.gov
   • hotmail.com
   • juno.com
   • msn.com
   • yahoo.com

Address generation for TO field:
To generate addresses it uses the following strings:
   • sandra; lolita; britney; bush; linda; julie; jimmy; jerry; helen;
      debby; claudia; brenda; anna; madmax; 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

It combines this with domains from the following list or from addresses found in files on the system

The domain is one of the following:
   • aol.com
   • cia.gov
   • fbi.gov
   • hotmail.com
   • juno.com
   • msn.com
   • yahoo.com

Avoid addresses:
It does not send emails to addresses containing one of the following strings:
   • avp; syma; icrosof; panda; sopho; borlan; inpris; example; mydomai;
      nodomai; ruslis; .gov; gov.; .mil; foo.; berkeley; unix; math; bsd;
      mit.e; gnu; fsf.; ibm.com; google; kernel; linux; fido; usenet; iana;
      ietf; rfc-ed; sendmail; arin.; ripe.; isi.e; isc.o; secur; acketst;
      pgp; tanford.e; utgers.ed; mozilla; be_loyal:; root; info; samples;
      postmaster; webmaster; noone; nobody; nothing; anyone; someone; your;
      you; bugs; rating; site; contact; soft; somebody; privacy; service;
      help; not; submit; feste; gold-certs; the.bat; page; admin; icrosoft;
      support; ntivi; unix; bsd; linux; listserv; certific; google; accoun;
      spm; fcnz; www; secur; abuse

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:
   • relay
   • mail1
   • mxs
   • mx1
   • smtp
   • gate
   • ns
   • 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 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 Servers:

Server: spm.slo-partija.info
Port: 48275
Server password: 57284
Channel: #hb2
Nickname: [I]%random character string%
Password: sp4m

Server: spm.gobice.net
Port: 48275
Server password: 57284
Channel: #hb2
Nickname: [I]%random character string%
Password: sp4m

Server: egwf.wegberobpk.info
Port: 48275
Server password: 57284
Channel: #hb2
Nickname: [I]%random character string%
Password: sp4m

– This malware has the ability to collect and send the following information:
    • Malware uptime

– Furthermore it has the ability to perform actions such as:
    • Download file
    • Execute file
    • Perform DDoS attack
    • Perform network scan

Hosts The host file is modified as explained:

– In this case existing entries are deleted.

– Access to the following domains is effectively blocked:
   • 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;
      www.avp.com; www.kaspersky.com; avp.com; www.networkassociates.com;
      networkassociates.com; www.ca.com; ca.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.microsoft.com; www.trendmicro.com; metalhead2005.info;
      irc.blackcarder.net; d66.myleftnut.info

The modified host file will look like this:

Miscellaneous Mutex:
It creates the following Mutex:
• I_FUCK_DEAD_PPL

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.

See a brief description here.

Description inserted by Victor Tone on Tue, 15 Nov 2005 09:08 (GMT+1)
Description updated by Victor Tone on Wed, 23 Nov 2005 14:37 (GMT+1)

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