Deloitte Security partner, Julie Priest said more than three-quarters (78 percent, up from 26 percent in 2005) of the world's leading 150 institutions surveyed confirmed a security breach from outside the organization.

"Almost half (49 percent, up from 35 percent in 2005) experienced at least one internal breach - confirming last year's survey findings that internal breaches are an increasing threat," she said.

The fourth annual survey found that the top three most common attacks the global financial industry experienced over the past 12 months, both externally and internally, aimed to extort for some form of monetary gain.

"Phishing and pharming accounted for more than half (51 percent) of the external attacks, followed by spyware or malware utilization (48 percent).

"Insider fraud (28 percent) and leakage of customer data (18 percent) were cited by respondents as among the top three most common internal breaches."