admin
31-01-2004, 02:27 AM
Virus Characteristics
This is a mass-mailing and peer-to-peer file-sharing worm that bears the following characteristics:
contains its own SMTP engine to construct outgoing messages
contains a backdoor component (see below)
contains a Denial of Service payload
If you think that you may be infected with Mydoom, and are unsure how to check your system, you may download the Stinger tool to scan your system and remove the virus if present. This is not required for McAfee users as McAfee products are capable of detecting and removing the virus with the latest update. (see the removal instructions below for more information).
Note: Receiving an email alert stating that the virus came from your email address is not an indication that you are infected as the virus often forges the from address.
The virus arrives in an email message as follows:
From: (Spoofed email sender)
Do not assume that the sender address is an indication that the sender is infected. Additionally you may receive alert messages from a mail server that you are infected, which may not be the case.
Subject: (Varies, such as)
Error
Status
Server Report
Mail Transaction Failed
Mail Delivery System
hello
hi
Body: (Varies, such as)
The message cannot be represented in 7-bit ASCII encoding and has been sent as a binary attachment.
The message contains Unicode characters and has been sent as a binary attachment.
Mail transaction failed. Partial message is available.
Attachment: (varies [.bat, .exe, .pif, .cmd, .scr] - often arrives in a ZIP archive) (22,528 bytes)
examples (common names, but can be random)
doc.bat
document.zip
message.zip
readme.zip
text.pif
hello.cmd
body.scr
test.htm.pif
data.txt.exe
file.scr
In the case of two file extensions, multiple spaces may be inserted as well, for example:
document.htm (many spaces) .pif
The icon used by the file tries to make it appear as if the attachment is a text file:
When this file is run (manually), it copies itself to the WINDOWS SYSTEM directory as taskmon.exe
%SysDir%\taskmon.exe
(Where %Sysdir% is the Windows System directory, for example C:\WINDOWS\SYSTEM)
It creates the following registry entry to hook Windows startup:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\
CurrentVersion\Run "TaskMon" = %SysDir%\taskmon.exe
The virus uses a DLL that it creates in the Windows System directory:
%SysDir%\shimgapi.dll (4,096 bytes)
This DLL is injected into the EXPLORER.EXE upon reboot via this registry key:
HKEY_CLASSES_ROOT\CLSID\{E6FB5E20-DE35-11CF-9C87-00AA005127ED}\InProcServer32 "(Default)" = %SysDir%\shimgapi.dll
The virus will not replicate on the 12th February or later (although the DLL will still be installed).
Peer To Peer Propagation
The worm copies itself to the KaZaa Shared Directory with the following filenames:
nuke2004
office_crack
rootkitXP
strip-girl-2.0bdcom_patches
activation_crack
icq2004-final
winamp
Remote Access Component
The worm (this functionality is in the dropped DLL) opens a connection on TCP port 3127 (if that fails it opens next available port up to port 3198). The worm can accept specially crafted TCP transmissions.
On receipt of one kind of such a transmission it will save the embedded binary into a temporary file and execute it. Then the temporary file is deleted.
On receipt of another kind it can relay TCP packets thus providing IP spoofing capabilities (possibly to facilitate SPAM distribution)
Denial of Service Payload
If the worm is run after February 1st 16:09:18 (UTC), it changes its behavior from mass mailing to initiating a denial of service attack against www.sco.com. This denial of service attack will stop on the first system startup after February 12th 02:28:57 (UTC) , and thereafter the worm's only behavior is to continue listening on TCP port 3127 (or up to 3198).
The denial of service executes by creating 64 threads each of which makes a HTTP GET request from random ports on the infected machines to port 80 of www.sco.com.
Indications of Infection
Upon executing the virus, Notepad is opened, filled with nonsense characters.
Existence of the files and registry entry listed above
Method of Infection
This worm tries to spread via email and by copying itself to the shared directory for Kazaa clients if they are present.
The mailing component harvests address from the local system. Files with the following extensions are targeted:
wab
adb
tbb
dbx
asp
php
sht
htm
txt
pl
The worm avoids certain address, those using the following strings:
.gov
.mil
abuse
acketst
arin.
avp
berkeley
borlan
bsd
example
fido
foo.
fsf.
gnu
google
gov.
hotmail
iana
ibm.com
icrosof
ietf
inpris
isc.o
isi.e
kernel
linux
math
mit.e
mozilla
msn.
mydomai
nodomai
panda
pgp
rfc-ed
ripe.
ruslis
secur
sendmail
sopho
syma
tanford.e
unix
usenet
utgers.ed
Additionally, the worm contains strings, which it uses to randomly generate, or guess, email addresses. These are prepended as user names to harvested domain names:
sandra
linda
julie
jimmy
jerry
helen
debby
claudia
brenda
anna
alice
brent
adam
ted
fred
jack
bill
stan
smith
steve
matt
dave
dan
joe
jane
bob
robert
peter
tom
ray
mary
serg
brian
jim
maria
leo
jose
andrew
sam
george
david
kevin
mike
james
michael
john
alex
Finally the virus sends itself via SMTP - constructing messages using its own SMTP engine. The worm guesses the recipient email server, prepending the target domain name with the following strings:
mx.
mail.
smtp.
mx1.
mxs.
mail1.
relay.
ns.
Removal Instructions
All Users :
Use specified engine and DAT files for detection and removal.
The shimgapi.dll file is injected into the EXPLORER.EXE process if the system has been rebooted after the infection has occured. In this situation, a reboot and rescan is required to remove this DLL from the system with the 4319 DAT files. The 4320 DAT files, and later, do not require a reboot.
Alternatively, following EXTRA.DAT packages are available.
EXTRA.DAT
SUPER EXTRA.DAT
Modifications made to the system Registry and/or INI files for the purposes of hooking system startup will be successfully removed if cleaning with the recommended engine and DAT combination (or higher).
Additional Windows ME/XP removal considerations
Stinger
Stinger 1.9.8 has been made available to assist in detecting and repairing this threat. A reboot is not required after running Stinger v 1.9.8.
Manual Removal Instructions
To remove this virus "by hand", follow these steps (WinNT/2K/XP):
Terminate the process TASKMON.EXE
Delete the file TASKMON.EXE from your WINDOWS SYSTEM directory (typically c:\windows\system32 or c:\winnt\system32)
Edit the registry
Delete the "TaskMon" value from
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Change the (Default) value to webcheck.dll here
HKEY_CLASSES_ROOT\CLSID\{E6FB5E20-DE35-11CF-9C87-00AA005127ED}\InProcServer32
Terminate the process EXPLORER.EXE
From the WINDOWS TASK MANAGER, click FILE - RUN, type EXPLORER.EXE and hit ENTER.
Delete the file SHIMGAPI.DLL your WINDOWS SYSTEM directory (typically c:\windows\system32 or c:\winnt\system32)
Reboot the system
McAfee Security Desktop Firewall
To prevent possible remote access McAfee Desktop Firewall users can block incoming TCP port 3127.
Sniffer Customers: Filters have been developed that will look for MyDoom traffic [Sniffer Distributed 4.1/4.2/4.3, Sniffer Portable 4.7/4.7.5, and Netasyst].
W32_MyDoom@MM Sniffer Filters.zip
ThreatScan users
The latest ThreatScan signature (2004-01-27) includes detection of the Mydoom virus. This signature is available for ThreatScan v2.0, v2.1, and v2.5.
ThreatScan users can also detect the backdoor portion of the virus by running a "Resource Discovery" task utilizing the port scanning options.
To update your ThreatScan installations with the latest signatures perform the following tasks:
From within ePO open the "Policies" tab.
Select "McAfee ThreatScan" and then select "Scan Options"
In the pane below click the "Launch AutoUpdater" button.
Using the default settings proceed through the dialogs that appear. Upon successful completion of the update a message will appear stating that; update 2004-01-27 has completed successfully.
From within ePO create a new "AutoUpdate on Agent(s)" task.
Go into the settings for this task and ensure that the host field is set to ftp.nai.com , the path is set to /pub/security/tsc20/updates/winnt/ and that the user and password fields are both set to ftp. Note that "tsc20" in the above path is used for ThreatScan 2.0 and 2.1. The correct path for ThreatScan 2.5 is "tsc25".
Launch this task against all agent machines.
When the task(s) complete information will be available in the "Task Status Details" report.
To create and execute a new task containing the new update functionality, do the following:
- Create a new ThreatScan task.
- Edit the settings of this task.
- Edit the "Task option", "Host IP Range" to include all desired machines to scan.
To scan for the virus:
Select the "Remote Infection Detection" category and "Windows Virus Checks" template. -or-
Select the "Other" category and "Scan All Vulnerabilities" template.
To create and execute a new task to perform a port scan, do the following:
Create a new Resource Discovery task.
Edit the settings of this task.
Edit the "Task option", "Host IP Range" to include all desired machines to scan.
To scan for the virus:
Select the "Port Scan" option.
Select the "TCP Port Scan" option.
Enter 3127 in the "TCP Port Ranges" field.
Launch the scan.
For additional information:
Run the "ThreatScan Template Report"
Look for module number #4061
admin
31-01-2004, 02:35 AM
W32.Mydoom.B@mm
Discovered on: January 28, 2004
Last Updated on: January 30, 2004 02:32:10 PM
W32.Mydoom.B@mm is a mass-mailing worm that arrives as an attachment with the file extension .bat, .cmd, .exe, .pif, .scr, or .zip.
When a computer is infected, the worm will set up a backdoor into the system, which can potentially allow an attacker to connect to the computer and use it as a proxy to gain access to its network resources.
In addition, the backdoor can download and execute arbitrary files.
The worm will perform a Denial of Service (DoS) against www.microsoft.com starting February 3, 2004 and www.sco.com starting February 1, 2004. It also has a trigger date to stop spreading on March 1, 2004. These events will only occur if the worm is run between or after those dates. While the worm will stop spreading on March 1, 2004, the backdoor component will continue to function after this date.
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Note:
Symantec Consumer products that support Worm Blocking functionality automatically detect this threat as it attempts to spread.
Symantec Security Response has developed a removal tool to clean the infections of W32.Novarg/Mydoom.
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Also Known As: Mydoom.B [F-Secure], W32/Mydoom.b@MM [McAfee], WORM_MYDOOM.B [Trend], Win32.Mydoom.B [Computer Associates], I-Worm.Mydoom.b [Kaspersky], W32/MyDoom-B [Sophos]
Variants: W32.Mydoom.A@mm, W32.Novarg.A@mm
Type: Worm
Infection Length: 29,184 bytes, 6,144 bytes
Systems Affected: Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows XP
Systems Not Affected: DOS, Linux, Macintosh, OS/2, UNIX
Virus Definitions (Intelligent Updater) *
January 28, 2004
Virus Definitions (LiveUpdate™) **
January 28, 2004
*
Intelligent Updater definitions are released daily, but require manual download and installation.
Click here to download manually.
**
LiveUpdate virus definitions are usually released every Wednesday.
Click here for instructions on using LiveUpdate.
Wild:
Number of infections: 0 - 49
Number of sites: 0 - 2
Geographical distribution: Low
Threat containment: Easy
Removal: Moderate
Threat Metrics
Wild:
Low
Damage:
Medium
Distribution:
High
Damage
Payload Trigger: n/a
Payload: n/a
Large scale e-mailing: Sends to email addresses found in a specified set of files.
Deletes files: n/a
Modifies files: n/a
Degrades performance: May perform a Denial of Service against www.microsoft.com and www.sco.com.
Causes system instability: n/a
Releases confidential info: n/a
Compromises security settings: Allows unauthorized remote access.
Distribution
Subject of email: Varies
Name of attachment: Varies with an extension of .pif, .scr, .exe, .cmd, .bat, or .zip.
Size of attachment: 29,184 bytes (varies if it is in .zip format)
Time stamp of attachment: n/a
Ports: TCP 80, 1080, 3128, 8080, 10080
Shared drives: n/a
Target of infection: n/a
When W32.Mydoom.B@mm is executed, it does the following:
Creates the following files:
%System%\Ctfmon.dll: Ctfmon.dll acts as a proxy server. The backdoor also has the ability to download and execute arbitrary files. It makes use of TCP ports 80, 1080, 3128, 8080, and 10080.
%Temp%\Message: This file contains random letters and is displayed using Notepad.
%System%\Explorer.exe.
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Notes:
Explorer.exe is a legitimate file in the Windows 95/98/Me operating systems, but is in the %Windir% folder, not the %System% folder. (By default, this is C:\Windows or C:\Winnt.) Do not delete the legitimate file that is in the %Windir% folder.
%System% is a variable: The worm locates the System folder and copies itself to that location. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
%Temp% is a variable: The worm locates the temporary folder and copies itself to that location. By default, this is C:\Windows\TEMP (Windows 95/98/Me), or C:\WINNT\Temp (Windows NT/2000), or C:\Document and Settings\<UserName>\Local Settings\Temp (Windows XP).
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Terminates the taskmon.exe process if it is running.
Adds the value:
"(Default)" = "%System%\ctfmon.dll"
to the registry key:
HKEY_CLASSES_ROOT\CLSID\{E6FB5E20-DE35-11CF-9C87-00AA005127ED}\InProcServer32
so that Explorer.exe loads Cftmon.dll.
Adds the value:
"Explorer" = "%System%\Explorer.exe"
to the registry keys:
HKEY_CURRENT_USER\Software\Microsft\Windows\Curren tVersion\Run
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Curr entVersion\Run
so that Explorer.exe is run when you start Windows.
Overwrites the local host file to prevent users from accessing the following sites. This action occurs at each instance the worm runs. If the local system date falls within the date range of the www.microsoft.com DoS, the reference to www.microsoft.com is not written to the hosts file.
ad.doubleclick.net
ad.fastclick.net
ads.fastclick.net
ar.atwola.com
atdmt.com
avp.ch
avp.com
avp.ru
awaps.net
banner.fastclick.net
banners.fastclick.net
ca.com
click.atdmt.com
clicks.atdmt.com
dispatch.mcafee.com
download.mcafee.com
download.microsoft.com
downloads.microsoft.com
engine.awaps.net
fastclick.net
f-secure.com
ftp.f-secure.com
ftp.sophos.com
go.microsoft.com
liveupdate.symantec.com
mast.mcafee.com
mcafee.com
media.fastclick.net
msdn.microsoft.com
my-etrust.com
nai.com
networkassociates.com
office.microsoft.com
phx.corporate-ir.net
secure.nai.com
securityresponse.symantec.com
service1.symantec.com
sophos.com
spd.atdmt.com
support.microsoft.com
symantec.com
update.symantec.com
updates.symantec.com
us.mcafee.com
vil.nai.com
viruslist.ru
windowsupdate.microsoft.com
www.avp.ch
www.avp.com
www.avp.ru
www.awaps.net
www.ca.com
www.fastclick.net
www.f-secure.com
www.kaspersky.ru
www.mcafee.com
www.microsoft.com
www.my-etrust.com
www.nai.com
www.networkassociates.com
www.sophos.com
www.symantec.com
www.trendmicro.com
www.viruslist.ru
www3.ca.com
Attempts to perform a DoS attack against www.microsoft.com and www.sco.com.
There is a 70% chance that the worm will perform the DoS against www.microsoft.com if the February 3, 2004 trigger date condition has been met.
There is an 80% change that the worm will perform the DoS against www.sco.com if the February 1, 2004 trigger date condition has been met.
The DoS against both sites consists of sending GET requests to the target domain using a direct connection to port 80. The date is taken by using the local system time.
Searches for the email addresses in the files that have the following extensions:
.htm
.sht
.php
.asp
.dbx
.tbb
.adb
.pl
.wab
.txt
Attempts to send email messages using its own SMTP engine. The worm looks up the mail server that the recipient uses before sending the email. It will prepend the following list of strings to the target domain name. If this is unsuccessful, it will use the local mail server instead.
gate.
ns.
relay.
mail1.
mxs.
mx1.
smtp.
mail.
mx.
The email will have the following characteristics:
From: The "From" address may be spoofed.
Subject: The subject will be one of the following:
Returned mail
Delivery Error
Status
Server Report
Mail Transaction Failed
Mail Delivery System
hello
hi
Message: The message will be one of the following:
sendmail daemon reported:
Error #804 occured during SMTP session. Partial message has been received.
Mail transaction failed. Partial message is available.
The message contains Unicode characters and has been sent as a binary attachment.
The message contains MIME-encoded graphics and has been sent as a binary attachment.
The message cannot be represented in 7-bit ASCII encoding and has been sent as a binary attachment.
Attachment:
The attachment may have either one or two file extensions. If it does have two, the first extension will be one of the following:
.htm
.txt
.doc
The second extension, or the only extension if there is only one, will be one of the following:
.pif
.scr
.exe
.cmd
.bat
.zip (This is an actual .zip file that contains a copy of the worm, sharing the same file name as the .zip. For example, readme.zip can contain readme.exe.)
If the worm has an extension of .exe or .scr, the file will be displayed with the following icon:
For all the other file extensions, it will use the icon for that file type.
Copies itself to the Kazaa download folder as one of the following files:
icq2004-final
Xsharez_scanner
BlackIce_Firewall_Enterpriseactivation_crack
ZapSetup_40_148
MS04-01_hotfix
Winamp5
AttackXP-1.26
NessusScan_pro
with a file extension of one of the following:
.pif
.scr
.bat
.exe
The worm also contains functionality which allows it to install itself on systems which may have been infected by W32.Novarg.A@mm. This is accomplished as follows:
The worm creates two to six threads working in parallel.
Each thread scans a randomly picked class-C sized networks, from a.b.c.1 to a.b.c.254, except that it skips networks where a=16, 224, 127 or 128.
Between each scanned network, a thread waits 128 ms.
Each IP in the scanned class-C is contacted on port 3127, if the connection succeeds, the worm sends an update command along with a copy of itself to be executed on the remote machine.
Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":
Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
If a blended threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
Removal using the Removal Tool
Symantec Security Response has developed a removal tool to clean the infections of variants of W32.Novarg/Mydoom. This is the preferred method in most cases.
Manual Removal
The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.
Disable System Restore (Windows Me/XP).
Remove the entries that were added to the Hosts file.
Update the virus definitions.
Restart the computer in Safe mode or VGA mode.
Run a full system scan and delete all the files detected as W32.Mydoom.B@mm.
Delete the values that were added to the registry.
Reregister the webcheck.dll file.
For specific details on each of these steps, read the following instructions.
1. Disabling System Restore (Windows Me/XP)
If you are running Windows Me or Windows XP, we recommend that you temporarily turn off System Restore. Windows Me/XP uses this feature, which is enabled by default, to restore the files on your computer in case they become damaged. If a virus, worm, or Trojan infects a computer, System Restore may back up the virus, worm, or Trojan on the computer.
Windows prevents outside programs, including antivirus programs, from modifying System Restore. Therefore, antivirus programs or tools cannot remove threats in the System Restore folder. As a result, System Restore has the potential of restoring an infected file on your computer, even after you have cleaned the infected files from all the other locations.
Also, a virus scan may detect a threat in the System Restore folder even though you have removed the threat.
For instructions on how to turn off System Restore, read your Windows documentation, or one of the following articles:
"How to disable or enable Windows Me System Restore"
"How to turn off or turn on Windows XP System Restore"
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Note: When you are completely finished with the removal procedure and are satisfied that the threat has been removed, re-enable System Restore by following the instructions in the aforementioned documents.
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For additional information, and an alternative to disabling Windows Me System Restore, see the Microsoft Knowledge Base article, "Antivirus Tools Cannot Clean Infected Files in the _Restore Folder," Article ID: Q263455.
2. Removing the entries that were added to the Hosts file
If the worm was successful in making changes to the Host file, it may prevent you from running LiveUpdate or accessing certain Web sites.
The Hosts file is not found on all the computers, and if it does exist, the location can vary. For example, if the file exists in Windows 98, it will usually be in C:\Windows; and in Windows 2000, it is in the C:\WINNT\SYSTEM32\DRIVERS\ETC folder. Also, there may be multiple copies of this file in different locations.
The most efficient way to locate the file is to search for it.
Follow the instructions for your operating system:
Windows 95/98/Me/NT/2000
Click Start, point to Find or Search, and then click Files or Folders.
Make sure that "Look in" is set to (C:) and that "Include subfolders" is checked.
In the "Named" or "Search for..." box, type:
hosts
Click Find Now or Search Now.
For each one that you find, right-click the file, and then click "Open With."
Deselect the "Always use this program to open this program" check box.
Scroll through the list of programs and double-click Notepad.
When the file opens, within the file, delete all the entries in the Hosts file where the line begins with 0.0.0.0.
For example:
0.0.0.0 www.microsoft.com
There may be many lines like this. Delete all of them.
Close Notepad and save your changes when prompted.
Windows XP
Click Start, and then click Search.
Click All files and folders.
In the "All or part of the file name" box, type:
hosts
Verify that "Look in" is set to "Local Hard Drives" or to (C:).
Click "More advanced options."
Check "Search system folders."
Check "Search subfolders."
Click Search.
Click Find Now or Search Now.
For each one that you find, right-click the file, and then click "Open With."
Deselect the "Always use this program to open this program" check box.
Scroll through the list of programs and double-click Notepad.
When the file opens, within the file, delete all the entries in the Hosts file where the line begins with 0.0.0.0.
For example:
0.0.0.0 www.microsoft.com
There may be many lines like this. Delete all of them.
Close Notepad and save your changes when prompted.
3. Updating the virus definitions
Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:
Running LiveUpdate, which is the easiest way to obtain virus definitions: These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate).
Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to the Virus Definitions (Intelligent Updater).
The Intelligent Updater virus definitions are available: Read "How to update virus definition files using the Intelligent Updater" for detailed instructions.
4. Restarting the computer in Safe mode or VGA mode
Shut down the computer and turn off the power. Wait for at least 30 seconds, and then restart the computer in Safe mode or VGA mode.
For Windows 95, 98, Me, 2000, or XP users, restart the computer in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode."
For Windows NT 4 users, restart the computer in VGA mode.
5. Scanning for and deleting the infected files
Start your Symantec antivirus program and make sure that it is configured to scan all the files.
For Norton AntiVirus consumer products: Read the document, "How to configure Norton AntiVirus to scan all files."
For Symantec AntiVirus Enterprise products: Read the document, "How to verify that a Symantec Corporate antivirus product is set to scan all files."
Run a full system scan.
If any files are detected as infected with W32.Mydoom.B@mm, click Delete.
6. Reversing the changes that were made to the registry
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WARNING: Symantec strongly recommends that you back up the registry before making any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify the specified keys only. Read the document, "How to make a backup of the Windows registry," for instructions.
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Click Start, and then click Run. (The Run dialog box appears.)
Type regedit
Then click OK. (The Registry Editor opens.)
Navigate to each of these keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Run
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\Curre ntVersion\Run
In the right pane, delete the value:
"Explorer"="%System%\explorer.exe"
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Note: %System% is a variable that refers to the location of the System folder. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
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Exit the Registry Editor.
7. Reregistering the Webcheck.dll file
Click Start, and then click Run. (The Run dialog box appears.)
Type, or copy and paste, the following text:
regsvr32 webcheck.dll
Click OK. When you see the message, "DllRegisterServer in webcheck.dll
succeeded," click OK.
Additional information:
When W32.Mydoom.B@mm sends email, it avoids distributing to the domains that contain any of the following strings:
avp
syma
icrosof
msn.
hotmail
panda
sopho
borlan
inpris
example
mydomai
nodomai
ruslis
.gov
gov.
.mil
foo.
berkeley
unix
math
bsd
mit.e
gnu
fsf.
ibm.com
google
kernel
linux
fido
usenet
iana
ietf
rfc-ed
sendmail
arin.
ripe.
isi.e
isc.o
secur
acketst
pgp
tanford.e
utgers.ed
mozilla
accounts that match any of the following strings:
root
info
samples
postmaster
webmaster
noone
nobody
nothing
anyone
someone
your
you
me
bugs
rating
site
contact
soft
no
somebody
privacy
service
help
not
submit
feste
ca
gold-certs
the.bat
page
or accounts that contain any of the following strings:
admin
icrosoft
support
ntivi
unix
bsd
linux
listserv
certific
google
accoun
The worm also prepends any of the following names to the domain name obtained to create randomly generated email addresses:
adam
alex
alice
andrew
anna
bill
bob
brenda
brent
brian
claudia
dan
dave
david
debby
fred
george
helen
jack
james
jane
jerry
jim
jimmy
joe
john
jose
julie
kevin
leo
linda
maria
mary
matt
michael
mike
peter
ray
robert
sam
sandra
serg
smith
stan
steve
ted
tom