A US operation which allegedly hit 600 blogs with spyware attached to free downloads has been temporarily shut down by a Los Angeles court pending further action by the Federal Trade Commission.

According to a CNET report, California-based Enternet Media disseminated its spyware via an affiliate programme in which webmasters were paid to include Enternet "installation boxes" in their websites. These boxes offered free music, ringtones or photos, but when a visitor downloaded the material it came with spyware attached which "tracked a user's Internet activity, changed their preferred home page settings, inserted a new toolbar onto their browsers, or displayed numerous 'pop up' ads on their computer screen", according to the FTC.

The LA court on Thursday issued a tempoarary restraining order against Enternet and three of its "officers" - Lida Rohbani, Nima Hakimi and Baback Hakimi, owners of various sites including Searchmiracle.com, c4tdownload.com and cash4toolbar.com. Also restrained was affiliate Nicholas C. Albert, whose website IWebtunes allegedly attracted 600 victims who downloaded music for use on their own sites, only to become spyware distributors themselves when Enternet installation boxes appeared on their blogs.

According to the FTC, the spyware was "very difficult for users to remove or uninstall". The Commission added that Google, Microsoft and Webroot had assisted in the investigation, without giving details.

An FTC spokesman said the Commission is "seeking a preliminary injunction against the defendants" and expects a hearing in the LA court soon.

This latest legal action against spyware operators comes hottish on the heels of FTC moves against New Hampshire-based Odysseus Marketing, alleged to have crammed victims' computers with dozens of programmes which "served up pop-ups, captured and transmitted information, and replaced and reformatted search results, serving up rigged results to place the defendants’ clients first", as we previously reported. ®