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Virus:Worm/NetSky.X
Date discovered:13/12/2012
Type:Worm
In the wild:Yes
Reported Infections:Medium
Distribution Potential:Medium
Damage Potential:Low
Static file:Yes
File size:24.064 Bytes
MD5 checksum:E6D771C24E8DBAF9543851E893C3E304
VDF version:7.11.53.216

 General Method of propagation:
   • Email


Aliases:
   •  Symantec: W32.Netsky.W@mm
   •  Mcafee: W32/Netsky.w@MM
   •  Kaspersky: Email-Worm.Win32.NetSky.x
   •  TrendMicro: WORM_NETSKY.W
   •  F-Secure: W32/Netsky.W@mm
   •  Grisoft: I-Worm/Netsky.CORRUPTED
   •  VirusBuster: I-Worm.Netsky.O
   •  Bitdefender: Win32.Netsky.X@mm


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


Side effects:
   • Drops malicious files
   • Uses its own Email engine
   • Registry modification

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



It copies itself within an archive to the following location:
   • %WINDIR%\zipped.tmp



The following files are created:

– MIME encoded copies of itself:
   • %WINDIR%\zip1.tmp
   • %WINDIR%\zip2.tmp
   • %WINDIR%\zip3.tmp
   • %WINDIR%\zip4.tmp
   • %WINDIR%\zip5.tmp
   • %WINDIR%\zip6.tmp
   • %WINDIR%\base64.tmp

 Registry The following registry key is added in order to run the process after reboot:

– [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   • "NetDy"="%WINDIR%\VisualGuard.exe"



The values of the following registry keys are removed:

–  [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   • Explorer
   • system
   • msgsvr32
   • service
   • DELETE ME
   • Sentry
   • Taskmon
   • Windows Services Host

–  [HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   • Explorer
   • au.exe
   • d3dupdate.exe
   • OLE
   • gouday.exe
   • rate.exe
   • Taskmon
   • Windows Services Host
   • sysmon.exe
   • srate.exe
   • ssate.exe

–  [HKCR\CLSID\{E6FB5E20-DE35-11CF-9C87-00AA005127ED}]
   • InProcServer32

 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.


To:
– Email addresses found in specific files on the system.


Subject:
The subject of the email is constructed out of the following:

    Sometimes it starts with one of the following:
   • RE:

    Sometimes continued by one of the following:
   • RE:

    Continued by one of the following:
   • read it immediately
   • important
   • improved
   • patched
   • corrected
   • approved
   • thanks!
   • hello
   • here
   • document_all
   • text
   • message
   • data
   • excel document
   • word document
   • bill
   • screensaver
   • application
   • website
   • product
   • letter
   • information
   • details
   • file
   • document


Body:
– Contains HTML code.

 
The body of the email is one of the following:

   • Your details.

   • Your document.

   • I have received your document. The corrected document is attached.

   • I have attached your document.

   • Your document is attached to this mail.

   • Authentication required.

   • Requested file.

   • See the file.

   • Please read the important document.

   • Please confirm the document.

   • Your file is attached.

   • "Please read the document.

   • Your document is attached.

   • Please read the attached file.

   • Please see the attached file for details.


Continued by the following:

   • %attachment filename%:No Virus Found
     Powered by the new Norton OnlineScan
     Get protected: www.symantec.com


Attachment:
The filename of the attachment is constructed out of the following:

–  It starts with one of the following:
   • document_all
   • text
   • message
   • data
   • excel document
   • word document
   • bill
   • screensaver
   • application
   • website
   • product
   • letter
   • information
   • details
   • file
   • document
   • important
   • approved

Sometimes continued by one of the following:
   • _%username from receiver's email address%

    The file extension is one of the following:
   • .zip
   • .pif
   • .exe
   • .scr



Here are a few examples of how the filename of the attachment might look like:
   • text_user.exe
   • excel document.pif



The email may look like one of the following:



 Mailing Search addresses:
It searches the following files for email addresses:
   • .xml; .wsh; .jsp; .msg; .oft; .sht; .dbx; .tbb; .adb; .dhtm; .cgi;
      .shtm; .uin; .rtf; .vbs; .doc; .wab; .asp; .php; .txt; .eml; .html;
      .htm; .pl

 Miscellaneous Mutex:
It creates the following Mutex:
   • NetDy_Mutex_Psycho


String:
Furthermore it contains the following strings:
   • "<*>NetDy: Thanks to the SkyNet alias NetSky crew for the sourcecode."
   • "<*>NetDy: We have rewritten NetSky."
   • "<*>NetDy: Thats a good tactic to detroy the bagle and mydoom worms."
   • "<*>NetDy: Our group will continue the war."
   • "<*>NetDy: Malware writers 'End' comes true."
   • "<*>NetDy: Our Social Engineering is the best *lol* (You have no virus symantec says!)."
   • "<*>NetDy: ----------------------------------------------------------------------------"
   • "<*>NetDy: We are greeting all russia people!"
   • "USA SUCKS!!! AFGHAN SUCKS 2!!! BURN, SADDAM! BURN IN HELL! AND YOU, OSAMA BIN LADEN,"
   • "BURN IN THE DEVILS FIRE 2!!!"
   • "SHAME ON YOU MR. BUSH!!!"
   • "YOURS SINCERELY: H."
   • "---> THIS IS A MESSAGE FROM: Skynet.cz-FANATICON"

 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 the following runtime packer:
   • UPX

Description inserted by Andrei Gherman on Friday, August 26, 2005
Description updated by Andrei Ivanes on Tuesday, March 14, 2006

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