A new brand of phishing attack now under way and aimed at legitimate Web site domain owners could be the result of efforts to shut down a notorious domain registrar popular among spammers and malware writers, security experts say.

The phishing emails, pretending to be from legitimate registrars eNom and Network Solutions Inc., attempt to fool domain name owners into giving up their account credentials. The eNom phishing email claims that eNom will be conducting database and data center maintenance, while the fake Network Solutions message says the customer needs to renew his or her expired domain registration.

Security experts say the timing of this phishing attack, complete with slick and authentic-looking messages and phony Web pages, is unlikely a coincidence. They say it may be the work of worried customers of EstDomains, which was terminated as an Internet domain registrar by the Internet Corporation for Assigned Names and Numbers (ICANN) earlier this week. But ICANN yesterday has ordered a stay on the termination process in order to check out EstDomains' response that its president, who has been convicted of credit card fraud, money laundering, and document forgery, left the company back in June. (ICANN cited the criminal charges against EstDomains' president as the premise for terminating the registrar).

The new phishing attacks are a way for spammers, malware writers, and fake antivirus writers to keep their operations running, whether or not EstDomains remains in business. "We believe this is tied to ICANN's decision" to terminate [EstDomains] domains, says Dmitry Samosseiko, manager of spam operations at SophosLabs. "There's no other reason for criminals to start phishing attacks on other registrars."

By grabbing legitimate domains, the cybercriminals secure safer cover for their operations. "With these phishing attacks, they'll get access to domains owned by good people. Some of the domains will have a reputation and will exist for a long period of time. It'll be hard or impossible for a registrar to shut down a domain owned by a good netizen without generating complaints," Samosseiko says. "As a result, it may create a bulletproof domain 'ownership,' even with registrars that take the abuse reports seriously."

EstDomains today operates around 281,000 domain names, according to ICANN estimates. eNom and Network Solutions each hold keys to millions of domain names -- eNom, around 9 million and Network Solutions, more than 6 million. If ICANN ends up shutting down EstDomains, its existing bad-guy customers would need a new way to bulk-register new domains, according to Sophos, which blogged about the phishing attacks Wednesday.

Still, the most organized and serious cybercriminals jumped the EstDomains' ship several months ago when it was apparent the heat was on the registrar, according to Samosseiko.

Registar phishing is just another way for the bad guys to get domain names for free, he says. "EstDomains is notorious for harboring [spammers and malware writers], but it's not the only one doing it," he says.

Have a comment on this story? Please click "Discuss" below. If you'd like to contact Dark Reading's editors directly, send us a message.