Why don't we call a spade a spade? You renamed an HTML file from "My Pics.html" to "My Pics.Folder", it's still an HTML file and not a folder. In fact, except for the changed file extension this is simply just a repeat of your previous post, "Self-Executing HTML: Internet Explorer 5.5 and 6.0 Part IV", except that the ".Folder" file extension is new to Windows XP and makes the file have a folder icon. When you open any file regardless of extension, Explorer tries to find the proper application to open the file with. This involves inspecting the first section of the files content and comparing it to a list of known signatures. You can read about "MIME Type Detection in Internet Explorer" at http://msdn.microsoft.com/workshop/networking/moniker/overview/appendix_a.asp We already know that opening HTML files from the My Computer zone is equivelant to opening an EXE file, given the executional rights provided by the zone. The only solution to this is to lock down the My Computer zone which I have been trying to advocate for some time now and Microsoft has now promised to do in Service Pack 2 for Windows XP. Regards Thor Larholm Senior Security Researcher PivX Solutions 24 Corporate Plaza #180 Newport Beach, CA 92660 http://www.pivx.com thor@pivx.com Phone: +1 (949) 231-8496 PGP: 0x5A276569 6BB1 B77F CB62 0D3D 5A82 C65D E1A4 157C 5A27 6569 PivX defines "Proactive Threat Mitigation". Get a FREE Beta Version of Qwik-Fix <http://www.qwik-fix.net> -----Original Message----- From: http-equiv@excite.com [mailto:1@MALWARE.COM] Sent: Sunday, January 25, 2004 8:51 AM To: NTBUGTRAQ@LISTSERV.NTBUGTRAQ.COM Subject: Self-Executing FOLDERS: Windows XP Explorer Part V Sunday, January 25, 2004 The following file is a 'folder' comprising both scripting and an executable [*.exe]. We inject scripting and an executable into the 'folder' which is designed to point back to the executable in the 'folder' and execute it. Provided the 'folder' is an html file, Windows XP Explorer will execute it. Because it is an 'folder' proper, Windows Explorer opens it. The scripting inside is then parsed and fired. That scripting is pointing back to the same executable file and because it is a self-executing 'folder', it executes ! Fully self-contained harmless *.exe. Windows XP only: http://www.malware.com/my.pics.zip Be aware of 'folders' out there. -- http://www.malware.com ----- Editor's Note: The 43rd Most Powerful Person in Networking says... Out of Office replies to list messages cause you to be unsubscribed automatically. Either subscribe a Public Folder, or ensure your rules are set to ensure list messages are filtered prior to your Out of Office reply. Such automatic replies are a bane to posters, and cause us to have fewer researchers post to NTBugtraq. -----