Experts say spam fight needs to be more strategic

Network World - The fight against spam has been too tactical and not strategic enough, according to experts at the Next Generation Networks conference in Boston.
"There's too much of the thinking, 'I've got a problem. How do I stop it from hurting me?'" said Phillip Hallam-Baker, principal scientist at VeriSign Inc. The thinking ought to be how to stop spam in general, he said.
"It's a public health problem. We have to look for ways to stop the infection from spreading to others," Hallam-Baker said.
Three approaches could work, said Paul Judge, chief technology officer at CipherTrust Inc. Filter spam so it never reaches desktops; train users to recognize and kill spam without responding to it or outlaw spam; and set up stiff penalties as a deterrent.
Spam can be limited by setting thresholds for cutting off e-mail from a single source address when more than a certain amount is sent per set time period, said Dean Drako, CEO of Barracuda Networks Inc.
Similarly, if a machine has been infected to generate spam, it can be cut off if it sends more than a certain amount in a given time period. About half of the machines used to spam are hijacked, said Hallam-Baker. Filters can also weed out spam based on keywords.
Phishers, whose e-mails seek to trick credit card and other financial information out of victims, use sets of commandeered machines to send their e-mails, Judge said. CipherTrust finds that phishers use about 1,000 such zombie machines per day, then switch to another battery of machines the next day. These zombie batallions range up to 15,000 in number, he said.
Hallam-Baker said ISPs should strip off all executables from their customers' e-mails to prevent creation of zombie computers. "It's a completely irrelevant capability that is only dangerous," he said.
Laws against spam throw potential legal hassles in front of spammers as well as the threat of financial penalties and the result of having all their e-mail blocked, Hallam-Baker said.
The downside is that antispam laws have had little effect. California passed an antispam law last year, Drako said. "There was no significant impact on spam being sent on the Internet," he said.
Hallam-Baker suggested a three-tiered registration system to stop spammers. Creating bonded senders could help by establishing a group of bulk e-mail senders who are likely not spammers. They would post a bond they would forfeit if they are caught spamming.
Senders would be authenticated via a lightweight DNS mechanism that would link the sender address to a small set of e-mail servers. If the address was lifted to send mail