We, the CERT/CC, along with other organizations listed below, are jointly publishing this alert about a serious threat to the Internet.
A Very Real and Present Threat to the Internet: Resurgence in Code Red Scanning Activity
Summary: The Code Red worm and mutations of the worm pose a continued and serious threat to Internet users. Immediate action is required to combat this threat. Users who have deployed software that is vulnerable to the worm (Microsoft IIS Versions 4.0 and 5.0) must install, if they have not done so already, a vital security patch.
How Big Is The Problem? On July 19, 2001, the Code Red worm infected more than 250,000 systems in just 9 hours. The worm scans the Internet, identifies vulnerable systems, and infects these systems by installing itself. Each newly installed worm joins all the others, causing the rate of scanning to grow rapidly. This uncontrolled growth in scanning directly decreases the speed of the Internet and can cause sporadic but widespread outages among all types of systems. Code Red has started spreading again and has mutated so that it may be even more dangerous. As of August 1, 2001, 16:30 EDT, over 100,000 hosts have already been compromised. This spread has the potential to disrupt business and personal use of the Internet for applications such as electronic commerce, email, and entertainment.
Who Must Act? Every organization or person who has Windows NT or Windows 2000 systems AND the IIS web server software may be vulnerable. IIS is installed automatically for many applications. If you are using Windows 95, Windows 98, or Windows Me, there is no action that you need to take in response to this alert.
What To Do If You Are Vulnerable
Microsoft's description of the patch and its installation, and the vulnerability it addresses is posted at http://www.microsoft.com/technet/treeview/default.asp?url=/technet/security/bulletin/MS01-033.asp
Because of the importance of this threat, this alert is being made jointly by
CERT and CERT Coordination Center are registered U.S. Patent and Trademark Office
Last updated August 1, 2001