ajx22
August 16th, 2003, 12:33 AM
W32.blaster worm
Discovered on: August 11, 2003
Last Updated on: August 15, 2003 04:35:37 PM
Virus and Security Bulletin
We would like to advise all members of a vulnerability in Microsoft operating systems that could be exploited by worms or viruses.
This Windows security vulnerability has allowed computers to be infected by the W32.Blaster.Worm. The worm exploits vulnerability in Microsoft software, and this issue potentially affects all Windows NT, 2000 & XP users.
Microsoft does offer a fix for this problem with the operating systems. All users are encouraged to apply the patches referred to in Microsoft Security Bulletin MS03-026 as soon as possible in order to mitigate the vulnerability that this worm is exploiting. These patches are available via Microsoft's Windows Update service.
http://www.microsoft.com/security/security_bulletins/ms03-026.asp
If you have anti-virus software already installed on your system, you should run an update in order to get the latest virus information, which should fix the issue with the worm. Please remember that Sympatico also offers anti-virus software, and that customers who subscribe to our anti-virus software are protected from the W32.Blaster Worm. If you don NOT have an Anti-Virus solution protecting your system - be sure to look into Norton AntiVirus from Symantec.
More info about Symantec products and their cost can be found @ Symantec Website (http://www.symantecstore.com/dr/sat2/ec_MAIN.Entry10?V1=30010186&SP=10024&PN=28&xid=27674&DSP=&CUR=840&PGRP=0&CACHE_ID=39910)
From Symantec website
Based on the number of submissions received from customers and based on information from Symantec's DeepSight Threat Management System, Symantec Security Response has upgraded this threat to a Category 4 from a Category 3 threat.
W32.Blaster.Worm is a worm that exploits the DCOM RPC vulnerability (described in Microsoft Security Bulletin MS03-026) using TCP port 135. The worm targets only Windows 2000 and Windows XP machines. While Windows NT and Windows 2003 Server machines are vulnerable to the aforementioned exploit (if not properly patched), the worm is not coded to replicate to those systems. This worm attempts to download the msblast.exe file to the %WinDir%\system32 directory and then execute it. The worm has no mass-mailing functionality.
Additional information, and an alternate site from which to download the Microsoft patch is available in the Microsoft article What You Should Know About the Blaster Worm and Its Variants.
Users are recommended to block access to TCP port 4444 at the firewall level, and then block the following ports, if they do not use the applications listed:
TCP Port 135, "DCOM RPC"
UDP Port 69, "TFTP"
The worm also attempts to perform a Denial of Service (DoS) on the Microsoft Windows Update Web server (windowsupdate.com). This is an attempt to prevent you from applying a patch on your computer against the DCOM RPC vulnerability.
NOTE: This threat will be detected by virus definitions having:
Defs Version: 50811s
Sequence Number: 24254
Extended Version: 8/11/2003, rev. 19
Symantec Security Response has developed a removal tool to clean infections of W32.Blaster.Worm.
W32.Blaster.Worm Webcast
The following webcast has been provided which details mitigation and remediation strategies as well as a detailed description of the DoS attack.
http://enterprisesecurity.symantec.com/content/webcastinfo.cfm?webcastid=63
Also Known As: W32/Lovsan.worm.a [McAfee], Win32.Poza.A [CA], Lovsan [F-Secure], WORM_MSBLAST.A [Trend], W32/Blaster-A [Sophos], W32/Blaster [Panda], Worm.Win32.Lovesan [KAV]
Type: Worm
Infection Length: 6,176 bytes
Systems Affected: Windows 2000, Windows XP
Systems Not Affected: Linux, Macintosh, OS/2, UNIX, Windows 95, Windows 98, Windows Me, Windows NT
Wild:
Number of infections: More than 1000
Number of sites: More than 10
Geographical distribution: High
Threat containment: Moderate
Removal: Moderate
Removal using the W32.Blaster.Worm Removal Tool
Symantec Security Response has developed a removal tool to clean infections of W32.Blaster.Worm. This is the easiest way to remove this threat and should be tried first. To obtain the W32.Blaster.Worm removal tool please see the following KB: W32.Blaster.Worm Removal Tool (http://securityresponse1.symantec.com/sarc/sarc.nsf/html/w32.blaster.worm.removal.tool.html)
Manual Removal
As an alternative to using the removal tool, you can manually remove this threat. The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.
For specific details, refer to the following instructions:
1. Restoring Internet connectivity
In many cases, on both Windows 2000 and XP, changing the settings for the Remote Procedure Call (RPC) service may allow you to connect to the Internet without the computer shutting down. To restore Internet connectivity to your PC please follow these steps:
Click Start > Run. The Run dialog box appears.
Type:
SERVICES.MSC /S
in the open line, and then click OK. The Services window opens.
In the right pane, locate the Remote Procedure Call (RPC) service.
--------------------------------------------------------------------------------
CAUTION: There is also a service named Remote Procedure Call (RPC) Locator. Do not confuse the two.
--------------------------------------------------------------------------------
Right-click the Remote Procedure Call (RPC) service, and then click Properties.
Click the Recovery tab.
Using the drop-down lists, change First failure, Second failure, and Subsequent failures to "Restart the Service."
Click Apply, and then OK.
--------------------------------------------------------------------------------
CAUTION: Make sure that you change these settings back once you have removed the worm.
--------------------------------------------------------------------------------
2. Ending the Worm process
Press Ctrl+Alt+Delete once.
Click Task Manager.
Click the Processes tab.
Double-click the Image Name column header to alphabetically sort the processes.
Scroll through the list and look for Msblast.exe.
If you find the file, click it, and then click End Process.
Exit the Task Manager.
3. Obtaining the latest 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:
For newer computer users
Running LiveUpdate, which is the easiest way to obtain virus definitions: Virus definitions for W32.Blaster.worm have been made available via the LiveUpdate server since August 11th, 2003. To obtain the latest virus definitions, click the LiveUpdate button from within the main user interface of your Symantec product. When running LiveUpdate, ensure that only "Norton AntiVirus Virus Definitions" are checked. Product updates can be obtained at a later time.
For system administrators and advanced users
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. 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.Blaster.Worm, click Delete.
5. Reversing the changes made to the registry
--------------------------------------------------------------------------------
CAUTION: 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.
--------------------------------------------------------------------------------
Click Start, and then click Run. (The Run dialog box appears.)
Type regedit
Then click OK. (The Registry Editor opens.)
Navigate to the key:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Curr entVersion\Run
In the right pane, delete the value:
windows auto update
Exit the Registry Editor.
6. Obtaining the Microsoft HotFix to correct the DCOM RPC vulnerability
W32.Blaster.Worm is a worm that exploits the DCOM RPC vulnerability using TCP port 135 to infect your PC. The W32.Blaster.Worm also attempts to perform a DoS on the Microsoft Windows Update Web server (windowsupdate.com) using your PC. To fix this, it is important to obtain the Microsoft Hotfix at: Microsoft Security Bulletin MS03-026.
Discovered on: August 11, 2003
Last Updated on: August 15, 2003 04:35:37 PM
Virus and Security Bulletin
We would like to advise all members of a vulnerability in Microsoft operating systems that could be exploited by worms or viruses.
This Windows security vulnerability has allowed computers to be infected by the W32.Blaster.Worm. The worm exploits vulnerability in Microsoft software, and this issue potentially affects all Windows NT, 2000 & XP users.
Microsoft does offer a fix for this problem with the operating systems. All users are encouraged to apply the patches referred to in Microsoft Security Bulletin MS03-026 as soon as possible in order to mitigate the vulnerability that this worm is exploiting. These patches are available via Microsoft's Windows Update service.
http://www.microsoft.com/security/security_bulletins/ms03-026.asp
If you have anti-virus software already installed on your system, you should run an update in order to get the latest virus information, which should fix the issue with the worm. Please remember that Sympatico also offers anti-virus software, and that customers who subscribe to our anti-virus software are protected from the W32.Blaster Worm. If you don NOT have an Anti-Virus solution protecting your system - be sure to look into Norton AntiVirus from Symantec.
More info about Symantec products and their cost can be found @ Symantec Website (http://www.symantecstore.com/dr/sat2/ec_MAIN.Entry10?V1=30010186&SP=10024&PN=28&xid=27674&DSP=&CUR=840&PGRP=0&CACHE_ID=39910)
From Symantec website
Based on the number of submissions received from customers and based on information from Symantec's DeepSight Threat Management System, Symantec Security Response has upgraded this threat to a Category 4 from a Category 3 threat.
W32.Blaster.Worm is a worm that exploits the DCOM RPC vulnerability (described in Microsoft Security Bulletin MS03-026) using TCP port 135. The worm targets only Windows 2000 and Windows XP machines. While Windows NT and Windows 2003 Server machines are vulnerable to the aforementioned exploit (if not properly patched), the worm is not coded to replicate to those systems. This worm attempts to download the msblast.exe file to the %WinDir%\system32 directory and then execute it. The worm has no mass-mailing functionality.
Additional information, and an alternate site from which to download the Microsoft patch is available in the Microsoft article What You Should Know About the Blaster Worm and Its Variants.
Users are recommended to block access to TCP port 4444 at the firewall level, and then block the following ports, if they do not use the applications listed:
TCP Port 135, "DCOM RPC"
UDP Port 69, "TFTP"
The worm also attempts to perform a Denial of Service (DoS) on the Microsoft Windows Update Web server (windowsupdate.com). This is an attempt to prevent you from applying a patch on your computer against the DCOM RPC vulnerability.
NOTE: This threat will be detected by virus definitions having:
Defs Version: 50811s
Sequence Number: 24254
Extended Version: 8/11/2003, rev. 19
Symantec Security Response has developed a removal tool to clean infections of W32.Blaster.Worm.
W32.Blaster.Worm Webcast
The following webcast has been provided which details mitigation and remediation strategies as well as a detailed description of the DoS attack.
http://enterprisesecurity.symantec.com/content/webcastinfo.cfm?webcastid=63
Also Known As: W32/Lovsan.worm.a [McAfee], Win32.Poza.A [CA], Lovsan [F-Secure], WORM_MSBLAST.A [Trend], W32/Blaster-A [Sophos], W32/Blaster [Panda], Worm.Win32.Lovesan [KAV]
Type: Worm
Infection Length: 6,176 bytes
Systems Affected: Windows 2000, Windows XP
Systems Not Affected: Linux, Macintosh, OS/2, UNIX, Windows 95, Windows 98, Windows Me, Windows NT
Wild:
Number of infections: More than 1000
Number of sites: More than 10
Geographical distribution: High
Threat containment: Moderate
Removal: Moderate
Removal using the W32.Blaster.Worm Removal Tool
Symantec Security Response has developed a removal tool to clean infections of W32.Blaster.Worm. This is the easiest way to remove this threat and should be tried first. To obtain the W32.Blaster.Worm removal tool please see the following KB: W32.Blaster.Worm Removal Tool (http://securityresponse1.symantec.com/sarc/sarc.nsf/html/w32.blaster.worm.removal.tool.html)
Manual Removal
As an alternative to using the removal tool, you can manually remove this threat. The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.
For specific details, refer to the following instructions:
1. Restoring Internet connectivity
In many cases, on both Windows 2000 and XP, changing the settings for the Remote Procedure Call (RPC) service may allow you to connect to the Internet without the computer shutting down. To restore Internet connectivity to your PC please follow these steps:
Click Start > Run. The Run dialog box appears.
Type:
SERVICES.MSC /S
in the open line, and then click OK. The Services window opens.
In the right pane, locate the Remote Procedure Call (RPC) service.
--------------------------------------------------------------------------------
CAUTION: There is also a service named Remote Procedure Call (RPC) Locator. Do not confuse the two.
--------------------------------------------------------------------------------
Right-click the Remote Procedure Call (RPC) service, and then click Properties.
Click the Recovery tab.
Using the drop-down lists, change First failure, Second failure, and Subsequent failures to "Restart the Service."
Click Apply, and then OK.
--------------------------------------------------------------------------------
CAUTION: Make sure that you change these settings back once you have removed the worm.
--------------------------------------------------------------------------------
2. Ending the Worm process
Press Ctrl+Alt+Delete once.
Click Task Manager.
Click the Processes tab.
Double-click the Image Name column header to alphabetically sort the processes.
Scroll through the list and look for Msblast.exe.
If you find the file, click it, and then click End Process.
Exit the Task Manager.
3. Obtaining the latest 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:
For newer computer users
Running LiveUpdate, which is the easiest way to obtain virus definitions: Virus definitions for W32.Blaster.worm have been made available via the LiveUpdate server since August 11th, 2003. To obtain the latest virus definitions, click the LiveUpdate button from within the main user interface of your Symantec product. When running LiveUpdate, ensure that only "Norton AntiVirus Virus Definitions" are checked. Product updates can be obtained at a later time.
For system administrators and advanced users
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. 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.Blaster.Worm, click Delete.
5. Reversing the changes made to the registry
--------------------------------------------------------------------------------
CAUTION: 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.
--------------------------------------------------------------------------------
Click Start, and then click Run. (The Run dialog box appears.)
Type regedit
Then click OK. (The Registry Editor opens.)
Navigate to the key:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Curr entVersion\Run
In the right pane, delete the value:
windows auto update
Exit the Registry Editor.
6. Obtaining the Microsoft HotFix to correct the DCOM RPC vulnerability
W32.Blaster.Worm is a worm that exploits the DCOM RPC vulnerability using TCP port 135 to infect your PC. The W32.Blaster.Worm also attempts to perform a DoS on the Microsoft Windows Update Web server (windowsupdate.com) using your PC. To fix this, it is important to obtain the Microsoft Hotfix at: Microsoft Security Bulletin MS03-026.