"We're receiving multiple reports of a phishing campaign using the template from a legitimate Microsoft email regarding Important Changes to Microsoft Services Agreement and Communication Preferences," Russ McRee, security incident handler at the SANS Internet Storm Center, said Saturday in a .

The rogue email messages are copies of legitimate notifications that Microsoft sent out to users to announce that will take effect Oct. 19.

However, in the malicious versions of the emails, the correct links have been replaced with links to compromised websites that host attack pages from the Blackhole exploit toolkit.

Blackhole is a tool used by cybercriminals to launch Web-based attacks that exploit vulnerabilities in browser plug-ins like Java, Adobe Reader or Flash Player, in order to install malware on the computers of users who visit compromised or malicious websites.

This type of attack is known as a drive-by download and is very effective because it requires no user interaction to achieve its goal.