Here are my DRAFT notes that may eventually appear on Symantec's threat info sites. ...Eric The CodeRed worm affects systems running Microsoft Index Server 2.0 or the Windows 2000 Indexing service. The worms uses a known buffer overflow contained in ISAPI.DLL. Information and a patch regarding this vulnerability can be found at: http://www.microsoft.com/technet/security/bulletin/MS01-033.asp. Administrators are encouraged to apply this patch to prevent infection from this worm and other unauthorized access. The worm sends its code via a HTTP request. This code exploits the buffer overflow causing the worm to be executed on the system. The code is not saved as a file, but injected and executed directly from memory. Patching ones system and rebooting will remove the worm and prevent further infection. In addition to seeking out new hosts to attack, the worm may attempt a denial of service attack. Also, the worm creates multiple threads (many of which simply sleep), which can cause instability of the system. Also Known As: W32/Bady Category: Worm Infection Length: 3569 Threat Assessment: [Medium] [Medium] [Low] Wild: Medium Damage: Medium Distribution: Low Wild: Number of infections: More than 1000 Number of sites: More than 10 Damage: Payload: Degrades performance: Will spawn multiple threads and utilize bandwidth. Causes system instability: Will spawn multiple threads. Distribution: Target of infection: Unpatched systems running Microsoft Index 2.0 or Windows 2000 Indexing Service Technical description: The worm sends its code as an HTTP request. The HTTP request exploits the buffer overflow causing the worm to be executed on the system. The malicious code is not saved as a file but injected and executed directly from memory. Once executed, the worm creates an empty file c:\notworm as a marker that the initial main thread has occured. New threads are then continuously created. The first 100 threads to attempt to exploit more systems by targetting random IP addresses, if the date is before the 20th. The worm will not make such HTTP requests to the IP address of 127.*.*.* thus, avoiding the loopback address. However, systems can become infected again. Further threads cause webpages to appear to be defaced if the system's default language US English. First, the thread sleeps 2 hours and then hooks a function, which responds to HTTP requests. Instead of returning the proper webpage, the worm returns its own HTML. The HTML displays: Welcome to http:// www.worm.com ! Hacked By Chinese! This hook lasts for 10 hours and then is removed. However, new threads that are created can then rehook the function. Also, if the date is between the 20th and 28th, the worm attempts a Denial of Service attack on a particular IP address by sending large amounts of junk data to a specific high port. Finally, if the date is greater than the 28th, the worm's threads simply are directed into an infinite sleep. The continual thread creation (many of which simply sleep) can cause system instability. Removal instructions: To remove the worm obtain and apply the patch located at http://www.microsoft.com/technet/security/bulletin/MS01-033.asp and restart the system. The file c:\notworm can also be deleted. ---------------------------------------------------------------------------- This list is provided by the SecurityFocus ARIS analyzer service. For more information on this free incident handling, management and tracking system please see: http://aris.securityfocus.com
This archive was generated by hypermail 2b30 : Thu Jul 19 2001 - 08:01:14 PDT