Harry Potter's latest cinematic adventure is already breaking box-office records, as the boy wizard encounters murder, betrayal and heartbreak at a theater near you. But a very different danger is plaguing his fans in cyberspace — where hackers are using the blockbuster to cast a spell on computers worldwide.

"It's definitely the most targeted film that we've seen," explained Michael Greene, VP of Product Strategy at PC Tools, whose virus fighters have been hard at work battling "Harry Potter hackers" over the last few weeks. "This is pretty scary stuff."

Here's how it works: These days, millions of people are searching the Web for info on "Harry Potter and the Half-Blood Prince," which is certain to become the #1 film in the country. Knowing this, cybercriminals are using paghahanap optimization tactics to target popular sites like Digg.com with headlines like "Watch 'Harry Potter and the Half-Blood Prince' online free!" and comment posts filled with related keywords to attract Google. Seeing professional-looking larawan from the film, Potter fans are convinced that the movie is one click away — but as they keep clicking, a virus is being installed on their computers.

"A couple of weeks nakaraan I started to notice it; there was a Digg post about viewing the new 'Harry Potter' movie in advance," Greene explained. "It tells you to download a video player — which is actually pretty common — if you watch a Flash movie or don't have the right software. But in this case, you're not getting a Flash plug-in or anything like that — what you're getting is the malware of the day.

"At that point, your computer has been infected," he added. "And even worse, you don't get to see the 'Harry Potter' movie."

The reason it's particularly scary is that these virus downloads are brazenly creeping onto legitimate Web sites — and teasing a largely youth-oriented fanbase with the forbidden prutas of a free, legal download. "In the old days, people would go to gambling sites or pornography sites and get infected — the dark underbelly of the Internet," Greene sinabi of the new hackers. "Viruses and malware would just trash your computer, and you might lose some data. Nowadays, it's a lot worse than that."

The Potter virus is categorized as crimeware, which searches your computer for credit card or bank information, Greene said. "[The hackers] will collect credit card details, social security numbers. Then they'll turn around and sell that to another group, a 'carding operation' they call it, and these guys will buy blank credit cards from a third group; they'll put them together, print out the credit cards and then sell physical credit cards with your numbers on the street."

The lesson, Greene explained, is a basic one: If you want to see "Half-Blood Prince," pay 10 bucks and get yourself to a movie theater. And if you're one of the many who've already attempted to download something too good to be true — get yourself a good antivirus program and begin cleaning up your computer, immediately.

"As long as there is money to be made, havoc to be created, there will be Voldemorts out there," Greene joked, comparing the Harry Potter hackers to the boy wizard's evil nemesis. "To keep Hogwarts running, we have to train the magicians to keep themselves safe."