WORM_NYXEM.E

This Worm arrives as attachment to mass-mailed email messages. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It uses the Windows Task Scheduler to add a scheduled task that executes the copies it drops. It bears the file icons of certain applications to avoid easy detection and consequent removal.

It disables the user's mouse and keyboard. This prevents users from removing this malware from the affected computer.

Arrival Details

This Worm arrives as attachment to mass-mailed email messages.

It may arrive via network shares.

It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Worm drops the following copies of itself into the affected system:

• %System%\scanregw.exe
• %System%\Update.exe
• %System%\Winzip.exe
• %Windows%\Rundll16.exe
• %Windows%\WINZIP_TMP.exe
• %System Root%\Documents and Settings\All Users\Start Menu\Programs\Startup\WinZip Quick Pick.exe

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

It drops the following non-malicious files:

• %System%\MSWINSCK.OCX
• %System%\{malware name}.zip

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It uses the Windows Task Scheduler to add a scheduled task that executes the copies it drops.

It bears the file icons of the following applications:

It terminates the execution of the copy it initially executed and executes the copy it drops instead.

Autostart Technique

This Worm adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
ScanRegistry = "scanregw.exe /scan"

The scheduled task executes the malware at the following period:

• execution time + 0:59

Other System Modifications

This Worm adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses
{default} = "Licensing: Copying the keys may be a violation of established copyrights."

It modifies the following registry key(s)/entry(ies) as part of its installation routine:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
WebView = "0"

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
CabinetState
FullPath = "1"

(Note: The default value data of the said registry entry is 0.)

It adds the following registry keys as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\096EFC40-6ABF-11cf-850C-08002B30345D

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\190B7910-992A-11cf-8AFA-00AA00C00905

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\2c49f800-c2dd-11cf-9ad6-0080c7e7b78d

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\4250E830-6AC2-11cf-8ADB-00AA00C00905

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\4D553650-6ABE-11cf-8ADB-00AA00C00905

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\556C75F1-EFBC-11CF-B9F3-00A0247033C4

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\57CBF9E0-6AA7-11cf-8ADB-00AA00C00905

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\5f54e750-ce26-11cf-8e43-00a0c911005a

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\6FB38640-6AC7-11cf-8ADB-00AA00C00905

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\72E67120-5959-11cf-91F6-C2863C385E30

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\78E1BDD1-9941-11cf-9756-00AA00C00908

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\7C35CA30-D112-11cf-8E72-00A0C90F26F8

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\899B3E80-6AC6-11cf-8ADB-00AA00C00905

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\9E799BF1-8817-11cf-958F-0020AFC28C3B

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\B1EFCCF0-6AC1-11cf-8ADB-00AA00C00905

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\BC96F860-9928-11cf-8AFA-00AA00C00905

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\E32E2733-1BC5-11d0-B8C3-00A0C90DCA10

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Licenses\F4FC596D-DFFE-11CF-9551-00AA00A3DC45

It modifies the following registry entries to hide files with Hidden attributes:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"

(Note: The default value data of the said registry entry is 1.)

It disables the user's mouse and keyboard.

Propagation

This Worm searches the network for the following shared networks onto which it attempts to drop copies of itself:

• \Admin$\WINZIP_TMP.exe
• \c$\Documents and Settings\All Users\Start Menu\Programs\Startup\WinZip Quick Pick.exe
• \c$\WINZIP_TMP.exe

It gathers target email addresses from files with the following extensions:

• .DBX
• .EML
• .HTM
• .IMH
• .MBX
• .MSG
• .NWS
• .OFT
• .VCF
• .MSF
• .TXT

It avoids sending email messages to addresses containing the following strings:

• @YAHOOGROUPS
• BLOCKSENDER
• YAHOO! MAIL -
• HOTMAIL.COM
• SCRIBE
• YAHOOGROUPS
• SYMANTEC
• MCAFEE
• VIRUS
• TREND
• PANDA
• SECUR
• SPAM
• NORTON
• ANTI
• CILLIN
• CA.COM
• KASPER
• TRUST
• AVG
• GROUPS.MSN
• NOMAIL.YAHOO.COM
• SCRIBE
• EEYE
• MICROSOFT

Information Theft

This Worm gathers the following data:

• Computer name

Stolen Information

This Worm sends the gathered information via HTTP POST to the following URL:

• http://{BLOCKED}ts.web.r{BLOCKED}gi-bin/Count.cgi?df=765247

Other Details

This Worm closes application windows that contain the following strings in the title bar:

• SYMANTEC
• SCAN
• KASPERSKY
• VIRUS
• MCAFEE
• TREND MICRO
• NORTON
• REMOVAL
• FIX

NOTES:

Upon execution, this opens its dropped non-malicious .ZIP file %System%\{malware name}.zip in order to trick users that a legitimate .ZIP file is executed.

It deletes the following files found in the following folder:

• %Program Files%\LimeWire\LimeWire 4.2.6\LimeWire.jar

It deletes all .DLL files found in the following folders:

• %Program Files%\DAP\
• %Program Files%\BearShare\
• %Program Files%\Grisoft\AVG7\
• %Program Files%\TREND MICRO\OfficeScan\
• %Program Files%\Morpheus\

It deletes all .EXE files found in the following folders:

• %Program Files%\Norton AntiVirus\
• %Program Files%\Alwil Software\Avast4\
• %Program Files%\McAfee.com\VSO\
• %Program Files%\Trend Micro\PC-cillin 2002\
• %Program Files%\Trend Micro\PC-cillin 2003\
• %Program Files%\Trend Micro\Internet Security\
• %Program Files%\NavNT\
• %Program Files%\Kaspersky Lab\Kaspersky Anti-Virus Personal\
• %Program Files%\Trend Micro\OfficeScan Client\
• %Program Files%\HyperTechnologies\Deep Freeze\

It deletes all .PPL files found in the following folder:

• %Program Files%\Kaspersky Lab\Kaspersky Anti-Virus Personal\

It deletes all files found in the following folders:

• %Program Files%\Symantec\LiveUpdate\
• %Program Files%\Symantec\Common Files\Symantec Shared\
• %Program Files%\McAfee.com\Agent\
• %Program Files%\McAfee.com\shared\

It deletes certain registry values if found in the following registry keys:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunServices

The following registry values are deleted if found in the above-mentioned registry keys:

• APVXDWIN
• AVG7_CC
• AVG7_EMC
• AVG7_Run
• AVGW
• AVG_CC
• Avgserv9.exe
• BearShare
• CleanUp
• DownloadAccelerator
• KAVPersonal50
• MCAgentExe
• MCUpdateExe
• MPFExe
• MSKAGENTEXE
• MSKDetectorExe
• McAfeeVirusScanService
• McRegWiz
• McVsRte
• NAV Agent
• NPROTECT
• OfficeScanNT Monitor
• PCCClient.exe
• PCCIOMON.exe
• PCCIOMON.exe
• PCClient.exe
• PccPfw
• Pop3trap.exe
• SSDPSRV
• ScanInicio
• ScriptBlocking
• TM Outbreak Agent
• VSOCheckTask
• Vet Alert
• VetTray
• VirusScan Online
• avast!
• ccApp
• defwatch
• kaspersky
• pccguide.exe
• rtvscn95
• tmproxy
• vptray

It searches the affected system for the existence of the following registry entries:

HKEY_LOCAL_MACHINE\kyLab\InstalledProducts\Kaspersky Anti-Virus
Personal Folder = {file path and file name}

HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\InstalledApps
NAV = {file path and file name}

HKEY_LOCAL_MACHINE\Software\INTEL\LANDesk\VirusProtect6\CurrentVersion
Home Directory = {file path and file name}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Panda Antivirus 6.0 Platinum
InstallLocation = {file path and file name}

HKEY_LOCAL_MACHINE\SOFTWARE\KasperskyLab\Components\101
Folder = {file path and file name}

Once found, it follows the registry value data and deletes all .EXE files found in the folder listed under the registry value data.

It also searches for the existence of the following registry entry:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\Iface.exe
Path = {file path and file name}

Once found, it follows the registry value data and deletes all .PPL files found in the folder listed under the registry value data.

It deletes all files found in the following shared folders:

• C$\Program Files\Norton AntiVirus
• C$\Program Files\Common Files\symantec shared
• C$\Program Files\Symantec\LiveUpdate
• C$\Program Files\McAfee.com\VSO
• C$\Program Files\McAfee.com\Agent
• C$\Program Files\McAfee.com\shared
• C$\Program Files\Trend Micro\PC-cillin 2002
• C$\Program Files\Trend Micro\PC-cillin 2003
• C$\Program Files\Trend Micro\Internet Security
• C$\Program Files\NavNT
• C$\Program Files\Panda Software\Panda Antivirus Platinum
• C$\Program Files\Kaspersky Lab\Kaspersky Anti-Virus Personal
• C$\Program Files\Kaspersky Lab\Kaspersky Anti-Virus Personal Pro
• C$\Program Files\Panda Software\Panda Antivirus 6.0
• C$\Program Files\CA\eTrust EZ Armor\eTrust EZ Antivirus

On the 3rd day of the month, it searches for files with the following file extensions:

• .doc
• .xls
• .mdb
• .mde
• .ppt
• .pps
• .zip
• .rar
• .pdf
• .psd
• .dmp

If found, it then overwrites it with the following strings:

• DATA Error [47 0F 94 93 F4 K5]

It displays the message, Update Please wait on Window's taskbar status area and the icon of the following folder if found:

• %Program Files%\Norton AntiVirus
• %Program Files%\Kaspersky Lab
• %Program Files%\Panda Software

It then drops the following files:

• %Program Files%\WinZip_Tmp.exe
• %Program Files%\Temp.Htt
• %Program Files%\desktop.ini

It uses its own Simple Mail Transfer Protocol (SMTP) engine to send email messages with a copy of itself as an attachment and that contains the following information:

Subject
• *Hot Movie*
• A Great Video
• Arab sex DSC-00465.jpg
• Fuckin Kama Sutra pics
• Fw:
• Fw: DSC-00465.jpg
• Fw: Funny :)
• Fw: Real show
• Fw: SeX.mpg
• Fw: Sexy
• Fwd: Crazy illegal Sex!
• Fwd: Photo
• Fwd: image.jpg
• Hello
• Miss Lebanon 2006
• My photos
• Part 1 of 6 Video clipe
• Re:
• Re: Sex Video
• School girl fantasies gone bad
• The Best Videoclip Ever
• Word file
• You Must View This Videoclip!
• eBook.pdf
• give me a kiss
• the file

Message body
• ----- forwarded message -----
• >> forwarded message
• ???????????????????????????? ????????????? ?????? ???????????
• Fuckin Kama Sutra pics
• Hot XXX Yahoo Groups
• Note: forwarded message attached.
• Please see the file.
• VIDEOS! FREE! (US$ 0,00)
• What?
• forwarded message attached.
• hello, i send the file. & vbCrLf & bye
• hi & vbCrLf & i send the details & vbCrLf & bye
• how are you? i send the details. OK ?
• i attached the details. & vbCrLf & vbCrLf & Thank you
• i just any one see my photos. It's Free :)
• ready to be FUCKED ;)

Attachment
• 007.pif
• 04.pif
• 3.92315089702606E02.UUE
• 677.pif
• Attachments00.HQX
• Attachments001.BHX
• Attachments[001].B64
• DSC-00465.Pif
• DSC-00465.pIf
• New_Document_file.pif
• Original Message.B64
• School.pif
• SeX.mim
• Sex.mim
• Video_part.mim
• WinZip.BHX
• Word_Document.hqx
• Word_Document.uu
• document.pif
• eBook.PIF
• eBook.Uu
• image04.pif
• photo.pif