It may be the biggest phishing catch of all time.
More than 110 million Target customers had their credit-card information stolen because at least one employee of a heating and air-conditioning contractor succumbed to an email phishing scheme, cybersecurity blogger Brian Krebs reported Wednesday.
The revelation, if true, is the strongest indication yet of what went wrong since Krebs first exposed the massive heist of consumer financial data at the national retail giant late last year, a startling cyberattack that has prompted intense congressional inquiry. Neiman Marcus and other chains have also recently been victimized, though it is not believed that the perpetrators are the same.
Last week, Krebs reported that hackers infiltrated Target's network by swiping the login credentials of Fazio Mechanical Services, a Pennsylvania-based contractor.
Now, anonymous sources tell Krebs that credentials "were stolen in an email malware attack at Fazio that began at least two months before thieves started stealing card data from thousands of Target cash registers." It appears that the culprits used a password-stealing bot known as Citadel to get the job done.
Fazio, in response to its sudden notoriety last week, sent out a statement explaining that it had been "the victim of a sophisticated cyberattack operation." But Krebs notes that the company's defense against malicious attacks was a free version of a somewhat impotent anti-malware program, which "is made explicitly for individual users and its license prohibits corporate use."
Members of Congress are calling for a bill to create a national reporting standard for data breaches similar to the one that hit Target. Retailers and financial institutions would be required to notify government and consumers of breaches when they occur.
The new revelations arrive on a day when the White House rolled out a set of voluntary guidelines intended to help businesses defend themselves against hackers.