F-Secure Virus Descriptions
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Alphabetical Index
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Radar Alert LEVEL 1
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| NAME: | Bugbear.B |
| ALIAS: | W32/Bugbear.B@mm, W32/Kijmo.A, I-Worm.Tanatos.B, Win32.Bugbear.B |
THIS VIRUS IS RANKED AS LEVEL 1 ALERT
UNDER F-SECURE RADAR.
For more information, see:
http://www.F-Secure.com/products/radar/
UPDATE (2003-06-05 15:00 GMT)
F-Secure is raising the alert level on Bugbear.B (Tanatos.B) to level 1
as it continues to spread rapidly. The number of reported infections
have increased drastically over the last 10 hours.
UPDATE (2003-06-05 9:55 GMT)
A new polymorphic virus - worm known as Bugbear.B is spreading in the
wild. The worm sends e-mails with various contents. It uses a known
vulnerability to execute the attachment automatically when the e-mail
is opened.
UPDATE (2003-06-05 7:30 GMT)
A new polymorphic variant of Bugbear worm (Bugbear.B) was found
in the wild early morning on June 5th, 2003.
Technical Description
The worm's file is a Windows PE executable file compressed with
UPX file compressor and encrypted with a simple cryptoalgorithm
that changes in every worm generation making the worm
polymorphic. The packed worm's file size is 72192 bytes, the
unpacked size is over 170 kilobytes.
Installation to system
When the worm's file is run, it installs itself to system by
infecting files of several popular applications and system tools.
The following files in Program Files and Windows folders are
infected:
%ProgramFilesDir%\winzip\winzip32.exe
%ProgramFilesDir%\kazaa\kazaa.exe
%ProgramFilesDir%\ICQ\Icq.exe
%ProgramFilesDir%\DAP\DAP.exe
%ProgramFilesDir%\Winamp\winamp.exe
%ProgramFilesDir%\AIM95\aim.exe
%ProgramFilesDir%\Lavasoft\Ad-aware 6\Ad-aware.exe
%ProgramFilesDir%\Trillian\Trillian.exe
%ProgramFilesDir%\Zone Labs\ZoneAlarm\ZoneAlarm.exe
%ProgramFilesDir%\StreamCast\Morpheus\Morpheus.exe
%ProgramFilesDir%\QuickTime\QuickTimePlayer.exe
%ProgramFilesDir%\WS_FTP\WS_FTP95.exe
%ProgramFilesDir%\MSN Messenger\msnmsgr.exe
%ProgramFilesDir%\ACDSee32\ACDSee32.exe
%ProgramFilesDir%\Adobe\Acrobat 4.0\Reader\AcroRd32.exe
%ProgramFilesDir%\CuteFTP\cutftp32.exe
%ProgramFilesDir%\Far\Far.exe
%ProgramFilesDir%\Outlook Express\msimn.exe
%ProgramFilesDir%\Real\RealPlayer\realplay.exe
%ProgramFilesDir%\Windows Media Player\mplayer2.exe
%ProgramFilesDir%\WinRAR\WinRAR.exe
%ProgramFilesDir%\adobe\acrobat 5.0\reader\acrord32.exe
%ProgramFilesDir%\Internet Explorer\iexplore.exe
%WinDir%\winhelp.exe
%WinDir%\notepad.exe
%WinDir%\hh.exe
%WinDir%\mplayer.exe
%WinDir%\regedit.exe
%WinDir%\scandskw.exe
where %ProgramFilesDir% is a Program Files directory and %WinDir%
is Windows directory.
The worm can also drop its file to Startup folder with a random
name or as SETUP.EXE, so it will be activated on next system
restart. Additionally the worm drops a keylogging component in
Windows System directory with a random name and DLL extension.
The name can be MGLKCKK.DLL for example. Also the worm creates 2
additional files in Windows System folder where it stores its
data in encrypted form.
Spreading in e-mails
The worm spreads in e-mail messages. It has its own SMTP engine.
To find e-mail addresses the worm looks for files with the
following names and extensions:
.ODS
.MMF
.NCH
.MBX
.EML
.TBB
.DBX
INBOX
Some of such files are e-mail databases and they contain a lot of
e-mail addresses. The worm sends itself to all found addresses.
However, it avoids sending itself to e-mail addresses containing
any of the following:
remove
spam
undisclosed
recipients
noreply
lyris
virus
trojan
mailer-daemon
postmaster@
root@
nobody@
localhost
localdomain
list
talk
ticket
majordom
The subject of an infected message is either taken from random
files on an infected computer or selected from the following
list:
Greets!
Get 8 FREE issues - no risk!
Hi!
Your News Alert
$150 FREE Bonus!
Re:
Your Gift
New bonus in your cash account
Tools For Your Online Business
Daily Email Reminder
News
free shipping!
its easy
Warning!
SCAM alert!!!
Sponsors needed
new reading
CALL FOR INFORMATION!
25 merchants and rising
Cows
My eBay ads
empty account
Market Update Report
click on this!
fantastic
wow!
bad news
Lost & Found
New Contests
Today Only
Get a FREE gift!
Membership Confirmation
Report
Please Help...
Stats
I need help about script!!!
Interesting...
Introduction
various
Announcement
history screen
Correction of errors
Just a reminder
Payment notices
hmm..
update
Hello!
The body of an infected message can be empty or it can contain a
text from a random file on an infected computer. The body of an
infected message can contain I-Frame exploit. It allows the worm
to run automatically on some computers when an infected e-mail is
viewed (for example, with Outlook and IE 5.0 or 5.01). This
vulnerability is fixed and a patch for it is available on
Microsoft site:
http://www.microsoft.com/windows/ie/downloads/critical/q323759ie/default.asp
The attachment name can be SETUP.EXE or it can contain one of the
following strings:
readme
Setup
Card
Docs
news
image
images
pics
resume
photo
video
music
song
data
The worm can also "borrow" a name from a random file on an
infected computer. The extension of an infected attachment is
selected from the following list:
exe
scr
pif
In case the worm used a file's name from an infected computer,
the worm's attachment can have 2 or more extensions, for example
DOCUMENT.DOC.EXE . The worm checks the extension of the file it
borrows the name from and sets the content type of its attachment
in an infected message accordingly.
Extensions the worm checks:
reg
ini
bat
h
diz
txt
cpp
c
html
htm
jpeg
jpg
gif
cpl
dll
vxd
sys
com
exe
bmp
Worm's attachment content types:
image/gif
image/jpeg
application/octet-stream
text/plain
text/html
The worm fakes sender's e-mail address, so if you receive an
infected message please do not reply to it as it will most likely
go to a person whose computer is not infected by the worm.
Please note that Bugbear.B worm can send out corrupted attachments
that will not run. Such attachments are usually shorter than the
original worm's file.
Spreading in local network
The worm has the ability to infect remote computers over a local
network. It waits for some time before starting its infection
cycle and then enumerates network shares, connects to them and
tries to infect the following files in Program Files and Windows
folders on remote computers:
%ProgramFilesDir%\winzip\winzip32.exe
%ProgramFilesDir%\kazaa\kazaa.exe
%ProgramFilesDir%\ICQ\Icq.exe
%ProgramFilesDir%\DAP\DAP.exe
%ProgramFilesDir%\Winamp\winamp.exe
%ProgramFilesDir%\AIM95\aim.exe
%ProgramFilesDir%\Lavasoft\Ad-aware 6\Ad-aware.exe
%ProgramFilesDir%\Trillian\Trillian.exe
%ProgramFilesDir%\Zone Labs\ZoneAlarm\ZoneAlarm.exe
%ProgramFilesDir%\StreamCast\Morpheus\Morpheus.exe
%ProgramFilesDir%\QuickTime\QuickTimePlayer.exe
%ProgramFilesDir%\WS_FTP\WS_FTP95.exe
%ProgramFilesDir%\MSN Messenger\msnmsgr.exe
%ProgramFilesDir%\ACDSee32\ACDSee32.exe
%ProgramFilesDir%\Adobe\Acrobat 4.0\Reader\AcroRd32.exe
%ProgramFilesDir%\CuteFTP\cutftp32.exe
%ProgramFilesDir%\Far\Far.exe
%ProgramFilesDir%\Outlook Express\msimn.exe
%ProgramFilesDir%\Real\RealPlayer\realplay.exe
%ProgramFilesDir%\Windows Media Player\mplayer2.exe
%ProgramFilesDir%\WinRAR\WinRAR.exe
%ProgramFilesDir%\adobe\acrobat 5.0\reader\acrord32.exe
%ProgramFilesDir%\Internet Explorer\iexplore.exe
%WinDir%\winhelp.exe
%WinDir%\notepad.exe
%WinDir%\hh.exe
%WinDir%\mplayer.exe
%WinDir%\regedit.exe
%WinDir%\scandskw.exe
where %ProgramFilesDir% is a Program Files directory and %WinDir%
is Windows directory.
Also the worm tries to locate common startup folder on remote
computers and copies itself there as SETUP.EXE or with a random
name and .EXE extension.
As a result remote computers will become infected either after
restart or after a user there runs an infected file.
Killing processes
The worm kills processes of certain anti-virus, security and
other programs. It lists active processes every 20 seconds and
terminates processes whose file names match any of the following:
_AVP32.EXE
_AVPCC.EXE
_AVPM.EXE
ACKWIN32.EXE
ANTI-TROJAN.EXE
APVXDWIN.EXE
AUTODOWN.EXE
AVCONSOL.EXE
AVE32.EXE
AVGCTRL.EXE
AVKSERV.EXE
AVNT.EXE
AVP.EXE
AVP32.EXE
AVPCC.EXE
AVPDOS32.EXE
AVPM.EXE
AVPTC32.EXE
AVPUPD.EXE
AVSCHED32.EXE
AVWIN95.EXE
AVWUPD32.EXE
BLACKD.EXE
BLACKICE.EXE
CFIADMIN.EXE
CFIAUDIT.EXE
CFINET.EXE
CFINET32.EXE
CLAW95.EXE
CLAW95CF.EXE
CLEANER.EXE
CLEANER3.EXE
DVP95.EXE
DVP95_0.EXE
ECENGINE.EXE
ESAFE.EXE
ESPWATCH.EXE
F-AGNT95.EXE
F-PROT.EXE
F-PROT95.EXE
F-STOPW.EXE
FINDVIRU.EXE
FP-WIN.EXE
FPROT.EXE
FRW.EXE
IAMAPP.EXE
IAMSERV.EXE
IBMASN.EXE
IBMAVSP.EXE
ICLOAD95.EXE
ICLOADNT.EXE
ICMON.EXE
ICSUPP95.EXE
ICSUPPNT.EXE
IFACE.EXE
IOMON98.EXE
JEDI.EXE
LOCKDOWN2000.EXE
LOOKOUT.EXE
LUALL.EXE
MOOLIVE.EXE
MPFTRAY.EXE
N32SCANW.EXE
NAVAPW32.EXE
NAVLU32.EXE
NAVNT.EXE
NAVW32.EXE
NAVWNT.EXE
NISUM.EXE
NMAIN.EXE
NORMIST.EXE
NUPGRADE.EXE
NVC95.EXE
OUTPOST.EXE
PADMIN.EXE
PAVCL.EXE
PAVSCHED.EXE
PAVW.EXE
PCCWIN98.EXE
PCFWALLICON.EXE
PERSFW.EXE
RAV7.EXE
RAV7WIN.EXE
RESCUE.EXE
SAFEWEB.EXE
SCAN32.EXE
SCAN95.EXE
SCANPM.EXE
SCRSCAN.EXE
SERV95.EXE
SMC.EXE
SPHINX.EXE
SWEEP95.EXE
TBSCAN.EXE
TCA.EXE
TDS2-98.EXE
TDS2-NT.EXE
VET95.EXE
VETTRAY.EXE
VSCAN40.EXE
VSECOMR.EXE
VSHWIN32.EXE
VSSTAT.EXE
WEBSCANX.EXE
WFINDV32.EXE
ZONEALARM.EXE
The worm has separate process killing routines for Windows 9x and
Windows NT-based operating systems.
Backdoor component
The worm has a backdoor component similar to the one used in its
previous version. The backdoor listens to TCP port 1080 for
commands from a remote host. A hacker can connect to the backdoor
and perform the following action:
- get information about infected computer
- upload and download files
- start files
- delete files
- terminate processes
- get process list
- start keylogger
- start HTTP server on a selected port
Here's how the interface of Bugbear's HTTP server looks like:
The Bugbear.B worm's backdoor does not use secure authentication
like its previous variant, so the backdoor can be used by many
hackers, not just the worm's author.
Affecting bank computers
The worm has a large list of domains belonging mostly to banks.
At startup the worm checks the domain name of an infected
computer and then compares it to the its internal list. If the
domain name matches, the worm can enable AutoDial feature on
an infected computer by modifying the following Registry key:
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"EnableAutodial"=dword:00000001
This is done to keep infected banks' workstations always on-line,
so the backdoor component could be accessible all the time after
infection. This makes easier for a hacker to use a keylogger and
other backdoor features to steal sensitive information. Such
actions make banks' computers more vulnerable than other infected
computers.
The list of bank domains that the worm has includes banks from
many different countries: France, UK, Germany, Australia, Italy,
Greece, Denmark, New Zealand, Spain, Brasil, Romania, Poland,
Argentina, Switzerland, Finland, Taiwan, Turkey, Iceland,
Slovakia, Korea, USA, South Africa, Baltic Republics, Austria,
Hungary, Norway, Czech Republic and some other countries.
Side Effect
According to reports, network printers start to print a lot of
garbage when the worm spreads in a network. This might be the
side-effect of the worm's attempts to infect a network.
Detection
F-Secure Anti-Virus detects Bugbear.B with the updates published
at 9:55 GMT on June 5th, 2003:
[FSAV_Database_Version]
Version=2003-06-05_02
Disinfection
F-Secure published additional update to disinfect Bugbear.B from
infected files on 9:56 GMT on June 6th, 2003:
[FSAV_Database_Version]
Version=2003-06-06_02
Disinfection Tool
F-Secure provides the special tool to disinfect Bugbear.B worm.
The tool and disinfection instructions are available on our ftp
site:
ftp://ftp.f-secure.com/anti-virus/tools/f-bugbr.zip
[Description: F-Secure Anti-Virus Research Team; F-Secure Corp.; June 5th-6th, 2003]
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