BEDFORD, Mass. (5/21/10)--Phishing attacks against U.S. entities decreased 5% in March, with attacks targeting credit unions declining 8%, according to the most recent RSA Online Fraud Report. The April Fraud Report, which covers March, was released by the Bedford, Mass.-based RSA Anti-Fraud Command Center. The study counted 17,559 attacks during March. Also declining were fast-flux attacks, with the number of attacks using this method decreasing 57%, said the report. RSA said the shift has had links to the diminished activity of the Rock Phish ganag and a cut-off of the AS-Troyak infrastructure that disconnected numerous malicious networks from the Internet. RSA continues to watch for a comeback by the Rock Phish gang, which is known to deliver attacks solely over its fast-flux infrastructure and bulletproof hosting. Fast flux refers to a method by which a domain name used by phishers has multiple internet provider (IP) addresses assigned to it. Phishers switch domains quickly among the addresses. That means the address is not easy to shut down. Instead of asking one IP provider to shut down the address, authorities must go to the domain name register, which is more time consuming. In March the number of brands attacked totaled 275--a decrease from February's 282 brands attacked. Brands that were attacked five times or less make up 56% of the total, RSA said. The number of entities experiencing their first phish attack in March dropped to 20 from 31 in February. This could indicate a focus by phishers to launch a larger number of attacks on a smaller number of brands, the company said. Regional bank brands--after being the most targeted among the financial sector in the U.S. for nine consecutive months--finally got a break. Nationwide bank brands became the most targeted brands in March, with a 29% hike in attacks, while regional banks fell 21% and credit unions fell 8%. Credit unions accounted for 4% of the attacks in March, compared with 22% of attacks in March 2009. Regional banks were targeted in 39% of phishing attacks, compared with 56% a year earlier. Nationwide U.S. banks bore the brunt of 57% of the attacks, compared with 11% in March 2009.