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Severity: High |
Microsoft Plug and Play Remote Code Execution and Elevation of Privilege Vulnerability / Zotob Worm
Overview : A remote code execution vulnerability exists in Microsoft Plug and Play (PnP). An attacker who successfully exploits this vulnerability can take complete control over an affected system.
PnP is used by the Microsoft Operating System to detect new hardware when it is installed.
Zotob is a worm that spreads by exploiting the Microsoft Windows Plug and Play service buffer overflow vulnerability (MS05-039). The worm also acts as an IRC-controlled backdoor, allowing a controller unauthorized access to the infected machine.
Description: The Zotob worm copies itself to the %System% directory as botzor.exe and modifies the registry to execute this copy at each Windows start:
- HKLM\Software\Microsoft\Windows\CurrentVersion\Run\WINDOWS SYSTEM = "botzor.exe"
- HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices\WINDOWS SYSTEM = "botzor.exe"
The worm searches random IP addresses for potential targets, checking for vulnerable systems via port 445. If it successfully exploits this vulnerability, the worm opens a remote shell on the target system, listening on port 8888. It then uses this shell to instruct the target to connect back to the source system and download the worm using the Windows FTP client. It downloads the worm to a file called "%System%\haha.exe", and runs it. It also creates a harmless file called "2pac.txt" in the process. To enable the FTP transfer, the worm acts as a very basic FTP server on the originating system, listening on port 33333.
Zone Labs products are not vulnerable to this attack. However, parts of the Microsoft Operating System are vulnerable. As such, this vulnerability has been classified as "High Risk." Computer users should take appropriate action to patch vulnerable systems.
Date Published : August 9, 2005
Date Last Revised : August 17, 2005
Impact : The Microsoft Plug and Play vulnerability enables an attacker to execute code on the target system with elevated privileges. The vulnerability can be exploited by a remote attacker sending a specially-crafted message to an affected system. The message could then cause the system to install malicious code (worm, virus, Trojan horse), read confidential data, or take control over the target system.
The Zotob worm exploits this vulnerability by modifying the Hosts file. The Hosts file contains the mappings of IP addresses to host names. Windows checks the Hosts file before it queries any DNS servers, which enables it to override addresses in the DNS. On XP, 2000 and NT systems the hosts file is located at %System%\drivers\etc\hosts: on 9x systems the hosts file is located at %Windows%\hosts. The worm modifies the Hosts file in order to restrict access to various hosts, including symantec.com and ca.com, as well as many others.
The Zotob worm can be used as an IRC controlled backdoor, allowing a remote user to gain unauthorized access to the infected machine.
Platforms Affected
Zotob worm can run on, and infect computers running Windows 2000.
Zotob worm can run on, but does not infect, computers running Windows 95/98/Me/NT4/XP. This means that these versions of Windows cannot be infected, but can still be used to infect vulnerable computers to which they are able to connect.
Please review the Microsoft Security Bulletin MS05-039 for a complete list of affected platforms: http://www.microsoft.com/technet/security/bulletin/MS05-039.mspx
Zone Labs Products
To ensure the most comprehensive protection, computer users should employ ZoneAlarm® Security Suite, or ZoneAlarm Pro. Zone Labs products are not vulnerable to this attack.
All Zone Labs security products, including ZoneAlarm, protect the user's system from unauthorized access and intrusions, and alert the user when malicious code attempts to access the network.
Recommended Actions:
ZoneAlarm Family
ZoneAlarm Pro and ZoneAlarm Security Suite protect your system against this vulnerability and the Zotob worm through "Internet Zone Security" and "Trusted Zone Security".
It is recommended that you ensure the following:
- Internet Zone Security is set to High .
- Trusted Zone Security is set to Medium .
- Only trusted hosts are in the ‘Trusted' Zone.
- Classic Firewall rules restrict TCP ports 139 and 445 to only trusted hosts. By default these ports are blocked by ZoneAlarm.
Zone Alarm Pro and ZoneAlarm Security Suite automatically protect your system, against the Zotob worm, by executing at Windows start through the "Triple Defense Firewall". This protection occurs because Zotab is blocked from modifying the registry.
Zone Alarm Pro and ZoneAlarm Security Suite automatically protect your system against the Zotob worm running through "Antivirus". This protection occurs because Zotab is a known virus that is blocked and killed.
Related Resources:
Contact : Zone Labs customers who are concerned about information contained in this advisory or have additional technical questions may reach our Technical Support team at: http://www.zonelabs.com/support/ . To report security issues with Zone Labs products contact security@zonelabs.com .
Disclaimer : The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information. Zone Labs and Zone Labs products, are registered trademarks of Zone Labs Incorporated. and/or affiliated companies in the United States and other countries. All other registered and unregistered trademarks represented in this document are the sole property of their respective companies/owners.
Copyright : ©2005 Zone Labs LLC All rights reserved. Zone Labs, TrueVector, ZoneAlarm, and Cooperative Enforcement are registered trademarks of Zone Labs LLC The Zone Labs logo, Check Point Integrity and IMsecure are trademarks of Zone Labs, Inc. Check Point Integrity protected under U.S. Patent No. 5,987,611. Reg. U.S. Pat. & TM Off. Cooperative Enforcement is a service mark of Zone Labs LLC All other trademarks are the property of their respective owners.
Any reproduction of this alert other than as an unmodified copy of this file requires authorization from Zone Labs. Permission to electronically redistribute this alert in its unmodified form is granted. All other rights, including the use of other media, are reserved by Zone Labs LLC.
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