eWeek reports that spammers" latest tactics are causing problems for the very backbone of the internet. They"re sending out e-mails pretending to be from non-existent domain names, in an attempt to disguise their true identities. Unfortunately, in doing so, they are beginning to cripple some DNS servers.
E-mails are being sent out late at night from an, at that point, unregistered domain. Many users won"t pick up the junk messages until the next morning - by which time the spammers have registered it. But in the interim, mail servers trying to check up on where the messages are coming from are beginning to cause problems. They attempt lookup the non-existent domain, something which is causing DNS servers delays, timeouts, and is backing up mail queues.
The scheme is the latest attempt of spammmers to get round the American CAN-SPAM legislation, aimed at cracking down on the problem. Introduced last year, it was designed to cut down on the amount of spam being sent. One way it did that was to make it illegal to send messages with faked "from" addresses.
Mail security firm CipherTrust"s chief technology officer, Paul Judge, warned: "Anti-spam systems have become heavily dependent on DNS for looking at all kinds of blacklists, looking at headers, all of that. I"ve seen systems that have to do as many as 30 DNS calls on each message. Even in large enterprises, it"s becoming very common to see a large spam load cripple the DNS infrastructure."