Microsoft is pushing out changes that will alter the configuration of its Windows 2000, XP and Windows Server 2003 operating systems. The changes will help customers fight off attacks that use web pages running Internet Information Server (IIS) as launching pads for malicious computer code.
The company has released an update that disables a Windows component called ADODB.Stream, which hackers were using to copy malicious code onto Windows users' machines, according to Stephen Toulouse, security programme manager in Microsoft's Security Response Centre.
Microsoft released the update one week after reports surfaced of website attacks by a Russian criminal hacking group called the Hangup Team. Some companies that failed to apply a recent software patch for Microsoft's IIS Version 5.0 web server fell victim to the attacks, in which hackers modified the configuration of IIS servers, allowing malicious code to be appended to every HTML (Hypertext Markup Language) document served from the web page.
Two vulnerabilities in Windows and the Internet Explorer web browser enabled attackers to silently run the malicious code on machines that visited the compromised sites, redirecting the customers to now-dormant websites controlled by the hackers from which a Trojan horse programme is unknowingly downloaded and installed on the user's system and used to capture sensitive information, such as account numbers, user names and passwords.
Microsoft is testing software patches to address other vulnerabilities exploited by the Hangup Team, including unpatched "cross zone scripting", which allows attackers to trick Internet Explorer into loading insecure content using relaxed security precautions typically applied to files stored on the local hard drive or obtained from a trusted website.
The next version of Windows XP, Service Pack 2, will also protect against the web attacks, even though it will not contain the new change that deactivates ADODB.Stream, Toulouse said.
Paul Roberts writes for IDG News Service