For those of you who need to get rid of this nasty worm, here\'s some info on the subject (from Symantec - symantec.com).
Discovered on: November 24, 2001
Last Updated on: November 27, 2001 at 09:32:11 AM PST
Due to the increased rate of submissions, Symantec Security Response has upgraded the threat level of this worm from level 3 to level 4 as of November 26, 2001.
W32.Badtrans.B@mm is a MAPI worm that emails itself out using different file names. It also creates the file \\Windows\\System\\Kdll.dll. It uses functions from this file to log keystrokes.
Infection Length: 29,020 bytes
Virus Definitions: November 24, 2001
Number of infections: More than 1000
Number of sites: 3 - 9
Geographical distribution: Low
Threat containment: Easy
Large scale e-mailing: Uses MAPI commands to send email.
Compromises security settings: Installs keystroke logging Trojan horse.
Name of attachment: randomly chosen from preset list
Size of attachment: 29,020 bytes
This worm arrives as an email with one of several attachment names and a combination of two appended extensions. It contains a set of bits that control its behavior:
001 Log every window text
002 Encrypt keylog
004 Send log file to one of its addresses
008 Send cached passwords
010 Shut down at specified time
020 Use copyname as registry name (else kernel32)
040 Use kernel32.exe as copyname
080 Use current filename as copypath (skips 100 check)
100 Copy to %system% (else copy to %windows%)
When it is first executed, it copies itself to %System% or %Windows% as Kernel32.exe, based on the control bits. Then it registers itself as a service process (Windows 9x/Me only). It creates the key log file \\%System%\\Cp_25389.nls and drops %System%\\Kdll.dll which contains the key logging code.
NOTE: %Windows% and %System% are variables. The worm locates the \\Windows folder (by default this is C:\\Windows or C:\\Winnt) or the \\System folder (by default this is C:\\Windows\\System or C:\\Winnt\\System32) and copies itself to that location.
A timer is used to examine the currently open window once per second, and to check for a window title that contains any of the following as the first three characters:
These texts form the start of the words LOGon, PASsword, REMote, CONnection, TERminal, NETwork. There are also Cyrillic versions of these same words in the list. If any of these words are found, then the key logging is enabled for 60 seconds. Every 30 seconds, the log file and the cached passwords are sent to one of these addresses:
After 20 seconds, the worm will shut down if the appropriate control bit is set.
If RAS support is present on the computer, then the worm will wait for an active RAS connection. When one is made, with a 33% chance, the worm will search for email addresses in *.ht* and *.asp in %Personal% and Internet Explorer %Cache%. If it finds addresses in these files, then it will send mail to those addresses. The attachment name will be one of the following:
In all cases, MAPI will also be used to find unread mail to which the worm will reply. The subject will be \"Re:\". In that case, the attachment name will be one of the following:
In all cases, the worm will append two extensions. The first will be one of the following:
The second extension that is appended to the file name is one of the following:
The resulting file name would look similar to CARD.Doc.pif or NEWS_DOC.mp3.scr.
If SMTP information can be found on the computer, then it will be used for the From: field. Otherwise, the From: field will be one of these:
\"Mary L. Adams\"
Email messages use the malformed MIME exploit to allow the attachment to execute in Microsoft Outlook without prompting. For information on this, go to:
The worm writes email addresses to the %System%\\Protocol.dll file to prevent multiple emails to the same person.
After sending mail, the worm adds the value
to the registry key
This will run the worm the next time that you start Windows.
To remove this worm, follow the instructions for your operating system.
1. Restart Windows in Safe Mode
2. Run Norton AntiVirus and delete all files that are detected as W32.Badtrans.B@mm.
3. Remove the value that it added to the registry.
For detailed instructions, see the sections that follow.
1. Rename the file Kernel32.exe.
2. Remove the value added to the registry.
3. Restart the computer.
4. Run Norton AntiVirus and delete all files that are detected as W32.Badtrans.B@mm.
For detailed instructions, see the sections that follow.
To restart 95/98/Me in Safe mode:
For instructions, read the document How to restart Windows 9x or Windows Me in Safe Mode.
To Rename the file Kernel32.exe under Windows NT/2000
1. Click Start, point to Find or Search, and click Files or Folders.
2. Make sure that \"Look in\" is set to (C and that Include subfolders is checked.
3. In the \"Named\" or \"Search for...\" box, type the following:
CAUTION: Make sure that you type the full name as shown. You must rename the Kernel32.exe file, not the legitimate Windows file Kernel32.dll
4. Click Find Now or Search Now.
5. Right-click the file that is displayed and then click Rename.
6. Rename the file to Kernel32.old and press Enter.
7. Close the Find or Search window.
8. Restart the computer.
To run Norton AntiVirus and delete detected files:
CAUTION: Make sure that you are in Safe mode (Windows 95/98/Me) or have already renamed the Kernel32.exe file (Windows NT/2000).
1. Run LiveUpdate to make sure that you have the most recent virus definitions.
2. Start Norton AntiVirus (NAV), and make sure that NAV is configured to scan all files. For instructions on how to do this, read the document How to configure Norton AntiVirus to scan all files.
3. Run a full system scan.
4. Delete all files that are detected as W32.Badtrans.B@mm.
To edit the registry:
CAUTION: We strongly recommend that you back up the system registry before you make any changes. Incorrect changes to the registry could result in permanent data loss or corrupted files. Please make sure that you modify only the keys that are specified. Please see the document How to back up the Windows registry before you proceed. This document is available from the Symantec Fax-on-Demand system. In the U.S. and Canada, call (541) 984-2490, select option 2, and then request document 927002.
1. Click Start, and click Run. The Run dialog box appears.
2. Type regedit and then click OK. The Registry Editor opens.
3. Navigate to the following key:
4. In the right pane, delete the following value:
5. Click Registry, and then click Exit.
Corporate email filtering systems should block all email that have attachments with the extensions .scr and .pif.
Home users should not open any email that has an attachment in which the second extension is .pif or .scr. Any email that has such an attachment should be deleted.
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