'Short, Brutal Lives': Life Expectancy for Malicious Domains

Domain Name System (DNS) pioneer Paul Vixie for more than three years has been calling for a "cooling off" period for newly created Internet domain names as a way to deter cybercrime and other abuses. Domain names registered and spun up in less than a minute only encourage and breed malicious activity, he argues, and placing them in a holding pattern for a few minutes or hours can help vet them and catch any registered by known spammers and other bad actors.

Vixie — who is founder and CEO of threat intelligence firm Farsight Security — and his team have now taken an up-close look at the life cycle of new Internet domains, and their findings shine new light on the lifespan of malicious and suspicious domains. "Most of them die young, and most of them die after living short, brutal lives," he says of newly created domains.

Over a six-month period, Vixie and his team conducted a longitudinal study of 23.8 million domains under 936 top-layer domains from their creation. They found that in the first seven days, 9.3% of new domains died: the median lifespan was four hours and 16 minutes.

The cause of death for 6.7% of those new domains was blacklisting, and most of them were blocked within an hour of their birth. DNS registrars and hosting providers, meanwhile, deleted or revoked malicious domains in three days or more after their creation. Interestingly, new generic top-level domains (gTLDs) suffered three times the rapid deaths than traditional ones such as .com, .net, .org, and .edu, for example.

Vixie's team found in the first week of life for new gTLDs there were 12 cases of more of them dying than living past their first week. "I was not shocked to see them as poster children of the short-lifetime effect," he says. "I don't know if they are more abusable or not," but it's possible the registries who snapped them up to sell aren't getting as much business as they expected. "They're under a good deal of financial pressure," he says, so some may be less choosy over to whom they sell their available domains.

The Internet's biggest TLD, .com, had just 2% of its new domains blacklisted and 3.6% deleted by registrars.

The new research, which Vixie will present on October 5 at the VirusBulletin International Conference in Montreal, underscores how a secure DNS policy is needed both for registrars that issue domains as well as enterprises that register new domains, he says. Putting new domains on ice for hours, days, or a week, is the best approach to ensure there's no malicious intent or ties. Enterprises, too, get the benefit of ensuring their new domains aren't incorrectly blacklisted, for example.

"All new domain should go into a penalty box — good or bad — until they've had a chance to live long enough," he says. Vixie's full report will be released on Friday.

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