F-Secure Virus Information Pages : Nyxem.E
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THIS VIRUS IS RANKED AS LEVEL
2
ALERT UNDER
F-SECURE RADAR.
Radar Alert LEVEL
2
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The 'Nyxem.e' is a mass-mailing worm that also tries to spread using remote shares. It also tries to disable security-related and file sharing software as well as destroys files of certain types. It is similar to the 'Email-Worm.Win32.VB.bi' that was found a few days ago.
Disinfection Utility
F-Secure Corporation provides the special disinfection utility to clean Nyxem.e infection from a computer. This disinfection utility is called F-Force and it can be downloaded from our web and ftp sites:
ftp://ftp.f-secure.com/anti-virus/tools/f-force.zip
http://www.f-secure.com/tools/f-force.zip
The utility is distributed only in a ZIP archive that contains the following files:
- f-force.exe - the main executable file
- eult.rtf - End User License Terms document
- readme.rtf - Readme file in RTF format
- readme.txt - Readme file in ASCII format
To unpack the archive please use the WinZip or similar archiver.
IMPORTANT! Please make sure that you read the End User License Terms document (Eult.rtf) and the Readme file (either Readme.txt or Readme.rtf) before using the F-Force utility!
The F-Force utility needs the archive with the latest updates in order to function properly. The archive's name is LATEST.ZIP and it should be downloaded and put into the same folder where the F-Force utility is located. This archive with the latest updates can be downloaded from these locations:
http://download.f-secure.com/latest/latest.zip
ftp://ftp.f-secure.com/anti-virus/updates/latest/latest.zip
Please note that the F-Force utility can disinfect only certain malicious programs. Besides the utility does not scan inside archives. So after cleaning a computer with the F-Force utility it is recommended to scan all hard drives with F-Secure Anti-Virus and the latest updates to make sure that no infected files remain there.
A trial version of F-Secure Anti-Virus and the latest updates can be downloaded from F-Secure's website:
http://www.f-secure.com/download-purchase/list.shtml
http://www.f-secure.com/download-purchase/updates.shtml
Installation to system
Nyxem.E is written in Visual Basic and is compiled as p-code. The size of the main executable is about 95 kilobytes. When the worm's file is run, it first opens WinZip as a decoy. On our test systems it also blocked keyboard and mouse so the only option was to press CTRL + ALT + DEL and to log off.
During the installation phase the worm copies its file to several locations:
%Windows%\rundll16.exe
%System%\scanregw.exe
%System%\Update.exe
%System%\Winzip.exe
where '%Windows%' presents the main Windows folder. On Windows systems, it is usually C:\WINDOWS\ folder. The '%System%' represents Windows System folder.
The worm creates the following Registry key value for its file to activate itself on every system startup:
[HKLM\Software\Microsoft\Windows\CurrentVersion\Run]
"ScanRegistry" = "%System%\scanregw.exe /scan"
Spreading in e-mails
The worm collects e-mail addresses from files with following extensions:
.HTM
.DBX
.EML
.MSG
.OFT
.NWS
.VCF
.MBX
.IMH
.TXT
.MSF
The worm searches for files with these extensions in Internet Explorer cache folders. E-mail addresses that have any of the following substrings are ignored by the worm:
SYMANTEC
MCAFEE
VIRUS
TREND
PANDA
SECUR
SPAM
NORTON
ANTI
CILLIN
CA.COM
KASPER
TRUST
AVG
GROUPS.MSN
NOMAIL.YAHOO.COM
SCRIBE
EEYE
MICROSOFT
@HOTMAIL
@HOTPOP
@YAHOOGROUPS
The worm sends itself as attachment in the infected e-mail. The e-mail subject can be one the following:
The Best Videoclip Ever
School girl fantasies gone bad
A Great Video
Fuckin Kama Sutra pics
Arab sex DSC-00465.jpg
give me a kiss
*Hot Movie*
Fw: Funny :)
Fwd: Photo
Fwd: image.jpg
Fw: Sexy
Re:
Fw:
Fw: Picturs
Fw: DSC-00465.jpg
Word file
eBook.pdf
the file
Part 1 of 6 Video clipe
You Must View This Videoclip!
Miss Lebanon 2006
Re: Sex Video
My photos
The message body may be one of the following:
Note: forwarded message attached.
Hot XXX Yahoo Groups
F*ckin Kama Sutra pics
ready to be F*CKED ;)
forwarded message attached.
VIDEOS! FREE! (US$ 0,00)
Please see the file.
>> forwarded message
----- forwarded message -----
i just any one see my photos. It's Free :)
how are you?
i send the details.
OK ?
The worm usually attached itself to e-mail messages as an executable file. It uses one the following names in attachment:
007.pif
School.pif
04.pif
photo.pif
DSC-00465.Pif
image04.pif
677.pif
New_Document_file.pif
eBook.PIF
document.pif
DSC-00465.pIf
Sometimes, the worm MIME-encodes the file. In these cases, the attachment name can be
one of the following:
Video_part.mim
Attachments00.HQX
Attachments001.BHX
Attachments[001].B64
3.92315089702606E02.UUE
SeX.mim
Sex.mim
Original Message.B64
WinZip.BHX
eBook.Uu
Word_Document.hqx
Word_Document.uu
The filename inside MIME-encoding is one of the following:
New Video,zip .sCr
Attachments,zip .SCR
Atta[001],zip .SCR
Clipe,zip .sCr
WinZip,zip .scR
Adults_9,zip .sCR
Photos,zip .sCR
Attachments[001],B64 .sCr
392315089702606E-02,UUE .scR
SeX,zip .scR
WinZip.zip .sCR
ATT01.zip .sCR
Word.zip .sCR
Spreading to network shares
The worm has several network spreading routines. One of them enumerates all available shares, then reads the values of the following Registry keys:
[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Recent"
"Personal"
The above Registry key values point to user's folders where personal documents and recently opened files are stored. If such foder is found, the worm opens it, enumerates files there, "borrows" one file name (randomly selected) and adds EXE extension to it. Then the worm copies itself to network shares with that name. If the worm does not find any files in those folders it copies itself to network shares with the following names:
New WinZip File.exe
Zipped Files.exe
movies.exe
The other network spreading routine searches for specific network shares and tries to copy itself using one of the following filenames:
\Admin$\WINZIP_TMP.exe
\c$\WINZIP_TMP.exe
\c$\Documents and Settings\All Users\Start Menu\Programs\Startup\WinZip Quick Pick.exe
At the same time the worm deletes the following file:
\c$\Documents and Settings\All Users\Start Menu\Programs\Startup\WinZip Quick Pick.lnk
Before spreading the worm checks whether a remote computer has any of the following folders and if it does, the worm tries to delete all files from that folder:
\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
The worm also creates a scheduled task to run the worm's files on remote computer with system priviledges at the 59th minute of the current hour.
Payload
The worm has a dangerous payload. If the date is equal to 3 (3rd of February, 3rd of March, etc) and the worm's UPDATE.EXE file is run, it destroys files with those extensions on all available drives:
*.doc
*.xls
*.mdb
*.mde
*.ppt
*.pps
*.zip
*.rar
*.pdf
*.psd
*.dmp
The files' contens get replaced with a text string "DATA Error [47 0F 94 93 F4 K5]". The payload is activated 30 minutes after the worm's file UPDATE.EXE is loaded into memory (basically 30 minutes after logon). We can confirm that the payload works at least on Windows XP. When the payload is activated, the worm enumerates all logical drives and damages files on them in a loop. So it should damage files on all drives that have a letter, including network drives. However the worm fails to do so on network drives at least in our test environment. Files on local and removable drives (including USB memory) were damaged by the payload.
The worm attempts to disable several security-related and file sharing programs. It deletes startup key values from the Registry if they contain any of the following:
NPROTECT
ccApp
ScriptBlocking
MCUpdateExe
VirusScan Online
MCAgentExe
VSOCheckTask
McRegWiz
CleanUp
MPFExe
MSKAGENTEXE
MSKDetectorExe
McVsRte
PCClient.exe
PCCIOMON.exe
pccguide.exe
Pop3trap.exe
PccPfw
PCCIOMON.exe
tmproxy
McAfeeVirusScanService
NAV Agent
PCCClient.exe
SSDPSRV
rtvscn95
defwatch
vptray
ScanInicio
APVXDWIN
KAVPersonal50
kaspersky
TM Outbreak Agent
AVG7_Run
AVG_CC
Avgserv9.exe
AVGW
AVG7_CC
AVG7_EMC
Vet Alert
VetTray
OfficeScanNT Monitor
avast!
DownloadAccelerator
BearShare
The following startup Registry keys are affected:
[HKLM\Software\Microsoft\Windows\CurrentVersion\Run]
[HKLM\Software\Microsoft\Windows\CurrentVersion\Run]
[HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices]
In addition the worm deletes files from the following subfolders in the Program Files folder:
\DAP\*.dll
\BearShare\*.dll
\Symantec\LiveUpdate\*.*
\Symantec\Common Files\Symantec Shared\*.*
\Norton AntiVirus\*.exe
\Alwil Software\Avast4\*.exe
\McAfee.com\VSO\*.exe
\McAfee.com\Agent\*.*
\McAfee.com\shared\*.*
\Trend Micro\PC-cillin 2002\*.exe
\Trend Micro\PC-cillin 2003\*.exe
\Trend Micro\Internet Security\*.exe
\NavNT\*.exe
\Kaspersky Lab\Kaspersky Anti-Virus Personal\*.ppl
\Kaspersky Lab\Kaspersky Anti-Virus Personal\*.exe
\Grisoft\AVG7\*.dll
\TREND MICRO\OfficeScan\*.dll
\Trend Micro\OfficeScan Client\*.exe
\LimeWire\LimeWire 4.2.6\LimeWire.jar
\Morpheus\*.dll
In addition the worm reads location of certain programs from Windows Registry and deletes certain files in these locations. The affected software is:
VirusProtect6
Norton AntiVirus
Kaspersky Anti-Virus Personal
Iface.exe
Panda Antivirus 6.0 Platinum
Also the worm closes application windows that have the following strings in their captions:
SYMANTEC
SCAN
KASPERSKY
VIRUS
MCAFEE
TREND MICRO
NORTON
REMOVAL
FIX
For some reason the worm adds several license keys to the Registry. Most of them seem to belong to VB6 controls. Also the worm makes the following changes to the Registry:
[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\CabinetState]
"FullPath" = dword:00000001
[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]
"ShowSuperHidden" = dword:00000000
[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]
"WebView" = dword:00000000
The worm can modify Active Desktop files in order to launch another copy of itself named 'WinZip_Tmp.exe' using the ActiveX control.
Infection counter
The worm has an interesting feature. When it infects a computer it opens a web browser on a certain webpage. This increments the counter on that webpage. We were contacted by the organization that runs the site with that counter. They informed us that the counter readings were not accurate. There were multiple hits from the same IPs to the counter. According to the latest information we received, the number of hits from unique IPs is over 300000 which is still quite big.
Other
The worm has the following text strings in its body:
mysoulmustfly
offlinehacker
evilpain
setthesun
Nyxem.E is detected with the following F-Secure Anti-Virus updates:[FSAV_Database_Version] Version = 2006-01-20_01
Technical Details: Alexey Podrezov, January 20, 2006
Description Updated: Alexey Podrezov, February 2, 2006
F-Secure Corporation
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