A number of Internet security firms have released reports in recent weeks blaming zombie-infected computers for anywhere between 40 percent and 65 percent of all spam — and placing much of the blame on adult webmasters.
Blumenthal said that on Tuesday his agency will send letters to ISPs around the world outlining steps they should take to combat zombie code.
One provision of the directive that may be of importance to adult webmasters calls for a technique called port-25 blocking, which prevents email from leaving an Internet service provider’s network without flowing through internal servers.
Among other side effects, port-25 blocking can prohibit webmasters from running their own mail servers, a common practice among those who prefer Linux environments.
For the most part, the FTC and its international partners are placing the burden of zombie fighting on ISPs.
In particular, they want ISPs to develop new techniques to spot and isolate computers generating suspect emails and help for customers to rid computers of zombie code.
But representatives of the ISP community have complained that such directives are misdirected and that they are as much victims of zombie attacks as anyone.
“It’s like walking up to a mugging victim and slapping them because they’re contributing to crime,” Dave McClure, president of the U.S. Internet Industry Association, said of the measure.
McClure said most zombie servers are hosted outside the United States and that U.S.-based ISPs have no control over zombie code that is hosted on foreign servers.
But Blumethal points out that many ISPs already are using the best practices his agency is recommending and that the FTC is working with dozens of international counterparts to help ISPs deal with Zombie attacks.