A former hacker has warned that there are thousands of people capable of hacking companies in the same way that Sony Pictures was hacked last year, and the software needed to perform the hack is being sold online.

Jon Miller, vice president of strategy at antivirus company Cylance, told "60 Minutes" that there are plenty of people online who are able to carry out an attack similar to the hack that crippled Sony Pictures in November 2014, CNET reports.

"There are probably a couple thousand, three, four, five-thousand people that could do [the Sony] attack today," Miller told "60 Minutes." He went on to explain that the technology used by the perpetrators of the Sony hack isn't a custom-made program. Instead, Miller says it can be purchased online from Russian hackers for around $30,000.

Miller isn't optimistic about the state of the internet, feeling that hackers are operating in a way that means police and governments simply can't catch them. "It truly, truly is the Wild West right now," he said. "What we're seeing are people getting pulled out onto the street and shot and it's like 'Where's the Sheriff?' There's no sheriff."

The hackers behind the Sony attack were never found, despite the US government publicly naming North Korea as being responsible for the hack. US Director of National Intelligence James Clapper spoke at a cybersecurity conference, and named a North Korean general as one of the men who would have had to authorise any North Korean hack. General Kim Youn Chol is a four star general in North Korea, and reportedly oversees the country's army of hackers.