TrojanDownloader:JS/Psyme.gen

TrojanDownloader:JS/Psyme.gen exploits a vulnerability known as the Navigation Method Cross-Domain Vulnerability, in the Web browser Internet Explorer to execute malicious Javascript. This malicious Javascript is commonly used to download and execute other malware on the affected system. 

 

On vulnerable systems, a remote code execution vulnerability exists in Internet Explorer because of the way that it handles navigation methods. An attacker could exploit this vulnerability by creating a malicious Web page or an HTML e-mail message and then enticing the user to visit this page or to view the HTML e-mail message. When the user visited the page or viewed the e-mail message, the attacker could access information from other websites, local files on the system, or cause script to run in the security context of the Local Machine Zone. If a user is logged on with administrative privileges, this could allow the attacker to take complete control of an affected system.

 

This vulnerability is corrected in Microsoft Security Update MS04-025, released in 2004.