WEST PALM BEACH, Fla. — April marked a massive jump in the number of unique phishing Web sites.

According to the Anti-Phishing Working Group Phishing Activity Trends Report, unique phishing Web sites increased nearly 35,000 from March to an April 2007 high of 55,643. Most sites were online an average of 2.8 days with the longest time online for a phishing site topping at 27 days.

APWG researchers encountered phishers placing thousands of phishing URLs under the same domain, similar to tactics employed by phishing gangs in late 2006. April also saw the number of brands being attacked rise to 174. Financial services continues to be the most targeted industry sector at 92.5% and the APWG notes that several large US banks are among the most attacked brands with the two top banks targeted for at least two months in a row. Here is a closer look at the APWG findings for the month of April.