A Cisco security report released on Thursday showed that hacker threats reached "startling levels" last year and that the world is suffering from a shortage of skilled computer defenders.

Cracks in defenses and weapons for attacks rose to the highest levels since tracking began in 2000, while there was a worldwide shortage of nearly a million skilled security professionals to protect networks and machines, according to the annual Cisco report.

"To truly protect against all of these possible attacks, defenders must understand the attackers, their motivations and their methods before, during and after an attack," said Cisco Threat Response Intelligence chief security officer John Stewart.

"Although the Cisco Annual Security Report paints a grim picture of the current state of cyber security, there is hope for restoring trust in people, institutions and technologies - and that starts with empowering defenders with real-world knowledge about expanding attack surfaces."

Technology and tactics used by online criminals have outpaced the ability of security professionals to defend against those threats, according to Cisco.

The problem is compounded by the fact that most organizations lack staff or systems to detect and counter hacker attacks quickly, the report concluded.

Hacker tactics include tricking people into revealing passwords or other sensitive information with ruses referred to as "social engineering" and taking advantage of trust relied on for financial, government or social activities online.

A sampling of 30 of the world's largest Fortune 500 companies showed that websites booby-trapped with malicious code were visited from each of their networks, according to the report.

Distributed denial of service attacks in which websites are overwhelmed by simultaneous requests were said to have increased in volume and severity.

Java continued to be the programming language most frequently exploited by cyber criminals, according to Cisco.

Meanwhile, 99 percent of all mobile viruses targeted devices powered by Google-backed Android software, with a typical tactic being to hide it in applications available for download at unofficial online marketplaces, the report indicated.

Cisco also reported "remarkable growth" in malware targeting the agriculture and mining industries, while seeing a continued rise in the energy, oil and gas sectors.

Silicon Valley-based Cisco Systems specializes in computer networking.