Virus:Worm/Opnis.T.1
Date discovered:24/08/2006
Type:Worm
In the wild:No
Reported Infections:Low
Distribution Potential:Medium
Damage Potential:Low to medium
Static file:Yes
File size:85.738 Bytes
MD5 checksum:7a44b326e90D03251af24e33826027ba
VDF version:6.35.01.132
IVDF version:6.35.01.135 - Thursday, August 24, 2006

 General Method of propagation:
   • Email


Aliases:
   •  Symantec: W32.Stration.B@mm
   •  Mcafee: W32/Stration@MM
   •  Sophos: W32/Dilworm-A
   •  VirusBuster: Trojan.Opnis.Z
   •  Bitdefender: Trojan.Downloader.Strationee.B


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


Side effects:
   • Downloads a malicious file
   • Uses its own Email engine


Right after execution it runs a windows application which will display the following window:


 Files It copies itself to the following location:
   • %WINDIR%\svchost32.exe



The following files are created:

– Non malicious file:
   • %WINDIR%\svchost32.xml

– %malware execution directory%\%hex number%.tmp



It tries to download a file:

– The location is the following:
   • http://gadesunheranwui.com/chr/jjjk/**********
It is saved on the local hard drive under: %TEMPDIR%\~%hex number%.tmp Furthermore this file gets executed after it was fully downloaded. Further investigation pointed out that this file is malware, too. Detected as: TR/Strationee.A

 Registry The following registry key is changed:

– HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UserData\
   S-1-5-18\Products\9040820900063D11C8EF00054038389C\Usage
   New value:
   • "OUTLOOKFiles"=dword:%hex number%

 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:
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.


Subject:
One of the following:
   • Error
   • Good day
   • hello
   • Mail Delivery System
   • Mail Transaction Failed
   • picture
   • Server Report
   • Status
   • test



Body:

 
The body of the email is one of the lines:
   • The message contains Unicode characters and has been sentas a binary attachment.
   • The message cannot be represented in 7-bit ASCII encodingand has been sent as a binary attachment
   • Mail transaction failed. Partial message is available.


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

–  It starts with one of the following:
   • body
   • data
   • doc
   • docs
   • document
   • file
   • message
   • readme
   • test
   • text

Continued by one of the following:
   • dat
   • elm
   • log
   • msg
   • txt

    Continued by one of the following:
   • bat
   • cmd
   • exe
   • pif
   • scr



Here are a few examples of how the filename of the attachment might look like:
   • body.dat.cmd
   • data.txt.pif

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:
   • xml; xls; wsh; wab; uin; txt; tbb; stm; shtm; sht; php; oft; ods; nch;
      msg; mmf; mht; mdx; mbx; jsp; html; htm; eml; dhtm; dbx; cgi; cfg;
      asp; adb


Address generation for FROM field:
To generate addresses it uses the following strings:
   • Barbara; Betty; Bill; Carol; Charles; Chris; Daniel; David; Don;
      Donna; Dorothy; Edward; Elizabeth; George; Helen; James; Jennifer;
      John; Joseph; Karen; Ken; Linda; Lisa; Margaret; Maria; Mark; Mary;
      Michael; Nancy; Patricia; Paul; Richard; Rob; Ron; Ruth; Sandra;
      Sharon; Steven; Susan; Tom

It may combine the first string with one of the following:
   • Adams; Allen; Anderson; Baker; Brown; Carter; Clark; Davis; Garcia;
      Gonzalez; Green; Hall; Harris; Hernandez; Hill; Jackson; Jones;
      Johnson; King; Lee; Lewis; Lopez; Martin; Martinez; Miller; Moore;
      Nelson; Robinson; Rodriguez; Scott; Smith; Taylor; Thomas; Thompson;
      Walker; White; Williams; Wilson; Wright; Young


The domain is one of the following:
   • care2.com; email.myway.com; fastmail.fm; gmail.com; goowy.com;
      hotmail.com; inbox.com; mail.aim.com; mail.com; mail.lycos.com;
      yahoo.com

Here you can find examples of generated addresses:
   • David Lee &ltDavid_1972@email.myway.com>
   • George Lopez &ltGeorge.Lopez@mail.lycos.com>
   • Mark Robinson &ltRobinson_vplxh@goowy.com>

 Backdoor Contact server:
The following:
   • http://gadesunheranwui.com/cgi-bin/**********

As a result it may send some information. This is done via the HTTP POST method using a CGI script.


Sends information about:
    • Current malware status

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

Description inserted by Ionut Slaveanu on Monday, August 28, 2006
Description updated by Ionut Slaveanu on Monday, September 11, 2006

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