Web security firm Finjan issued a warning Thursday about a new wave of mass Web attacks that it said has affected more than 1,000 Web site domains, including government, retail, healthcare and advertising sites. Security vendors have been aware of the attack toolkit, dubbed “Asprox,” for several years. However, they have noticed an uptick in the popularity of the malware since 2007. In May, cyber-criminals began a new round of mass Web attacks that successfully targeted a large number of government and top business Web sites around to the world, the firm said.