The US Sony Playstation Web site is the latest high-profile victim of a hacker attack on business sites that's spreading malware at breakneck pace, says a security vendor.

Sophos reported that Sony had suffered an SQL injection attack last Wednesday. Malicious code was planted on pages of two popular Playstation games -- SingStar Pop and God of War.

The digital security company alerted Sony to the problem, and it was fixed as of early last Thursday morning, says Graham Cluley, senior technology consultant with Sophos headquartered in the UK.

While the Playstation site is now clean, hundreds of other Web sites have been compromised by the same attack, he says. Affected sites are wide ranging, says Cluley, "from Brazilian and Chinese government sites to a garden pond supplier in Canada."

The SQL injection attack is an old hacker trick that has found new life.

Its usage in recent months has soared, as cyber criminals use automated programs to scour the Web for pages and sites vulnerable to such exploits.

The attacks have transformed thousands of credible business Web pages on sites such as MSNBC into malware-peddling portals.

Attacks have ballooned in recent months. There is now a new malware-infected Web page every five seconds, according to Sophos. That's three times the rate of infection compared to last year. Eight out of 10 Web sites suffering from the attack are legitimate business Web sites.

"There's been a spate of attacks being called by a botnet named Asprox," Cluley says. "It's using innocent people's computers to go on the Web and find vulnerable targets."

An automated attack is to blame for the Sony hack, he adds. It wasn't launched by a person, but an automated program that stumbled upon the code vulnerability on the Playstation pages and took advantage.

The attacks don't exploit a specific software vulnerability, but take advantage of poor coding practices, according to a Microsoft Security Advisory. Companies that access and manipulate data in a relational database such as SQL Server from a Web site are at risk.

It comes down to a problem with a Web application, says Brian Bourne, president of Canada-based security analyst firm CMS Consulting. Developers are failing to do proper code checking to prevent the attacks.

"They're not doing input validation," he explains. "They're not looking at it and saying 'hey, this is not regular user input' -- that's the simple version."

But Web administrators have to shoulder the burden of blame too, Bourne adds. They're responsible for creating a layered security approach to protect against known and yet-to-be-discovered exploits.