* In the Internet Options dialog box, click the Security tab and then click the "Internet" icon.

* Under Security level for this zone, move the slider to "High." This sets the security level for all Web sites you visit to High. (If no slider is visible, click the Default Level button and then move the slider to High.)

Note: The High setting may cause some Web sites to work improperly. If you have difficulty using a Web site after you change this setting and you are sure the site is safe to use, you can add that site to your list of trusted sites. This will allow the site to work properly even with the high security setting.

Other instructions and information:

Symantec published a writeup on the malicious code.

According to SANS, users whose computers have been victimized by this attack may notice one or more of the following:

* A warning about a javascript error. But it depends on how the attack code interferes with other javascript on the respective page, and many users disable these javascript warnings.

* Antivirus software may detect the javascript as "JS.Scob.Trojan," but that warning may pop up numerous times for each Web page visited, as the malicious code is appended to every file on the Web server, including images.

– Brian Krebs, washingtonpost.com staff writer