Hackers are leveraging the popularity of a summer blockbuster to dish out malware, according to anti-virus provider ThreatFire. Links related to the new “Harry Potter” movie are popping up across the web, especially on sites such as Digg.com and Blogspot.com, the company said Thursday in a blog post. If users follow the link, they are brought to a site claiming to offer a video of the movie but actually tries to get them to install a host of malware, including the Koobface worm and rogue anti-virus programs. — DK