The Syrian Electronic Army's (SEA) breach of CNN's social media accounts on Friday was the product of an intense, sophisticated phishing attack, according to a news report.

Quoting "a source with knowledge of the attack," the website Mashable reports that the SEA sent multiple waves of phishing messages to CNN employees that were well-written and appeared to come from CNN email addresses.

A CNN employee fell for the ruse, revealing his password on a fake login page, according to the report. This enabled the SEA to gain access to the user's HootSuite account, which, in turn, enabled them to access multiple CNN social media accounts.

The SEA used this access to post messages on CNN's Twitter and other accounts, according to the news report. "The Syrian Electronic Army was here... Stop lying... All your reports are fake!" the tweets stated. CNN responded quickly to the breach, and the posts were seen only briefly. The SEA attackers were also able to post fake stories on CNN blogs, using the employee's Wordpress account.

According to the report, the SEA then sent another wave of phishing emails, this time using victims' actual email accounts, warning of an attack and fooling at least five more users into giving up their passwords on a fake page.

The attacks are far from the SEA's first on U.S.-based media and social networks. In a report issued last week, the threat intelligence firm CrowdStrike offered a detailed profile of the SEA, a group of organized attackers that it calls Deadeye Jackal.

The CrowdStrike report outlines the SEA's attacks on the Associated Press and other media, including attacks on third-party communications and DNS providers that ultimately targeted The New York Times, The Washington Post, The Financial Times, and Twitter feeds for Reuters, AP, and BBC Weather.

The CNN attack is consistent with other attacks that the SEA has launched on media and social networks, says Adam Meyers, vice president of intelligence at CrowdStrike.

"We have observed a notable increase in [the SEA's] activity over the entirety of 2013, and they came into 2014 going strong, running a series of credential harvesting campaigns, Twitter account takeovers, and website defacements against CNN and Microsoft," he says.

Lucas Zaichkowsky, enterprise defense architect at incident response firm AccessData, notes that if the reports about a breach of an employee's HootSuite account are true, the attack might have been preventable.

"HootSuite supports two-factor authentication, which would have most likely thwarted the attacker had the CNN social media staff members enabled it," Zaichkowsky observes.

But Scott Greaux, vice president of anti-phishing vendor PhishMe, says two-factor authentication and identity management are only part of the solution.

"These are valid arguments, but the most important thing to remember is that these attacks are targeting employees and may not have succeeded if the employees had more knowledge of the potential security risks associated with email," Greaux says. "Fortifying the human element by cultivating a user base that recognizes malicious email is an important defense against the types of attacks the SEA has carried out with such success."

Employees should know whether their IT departments would normally require password changes via email, and if they are unsure about a message, they should verify it with a phone call to the sender, Greaux says. Employees should also be trained to examine the URL of sites that require passwords -- a quick look will sometimes reveal that the site is a fake, he observes.

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