89 percent of security breaches go unreported

Security incidents, as defined by the study, represent "an unexpected activity that brought sudden risk to the organization and took one or more security personnel to address."

Some of the security incidents, such as the e-mail-borne malware and phishing that affected 69% of respondents' companies, may not have led to serious consequences in every instance. But 29% of those answering the survey said their organizations experienced customer or employee data leakage. Twenty-eight percent reported insider threats or theft and 16% reported intellectual property theft.

"With 29% of respondents stating that they experienced the leakage of employee or customer data in 2007, it is alarming to see that only 11% of those types of incidents went reported," said Tim Mather, chief security strategist for RSA Conference, in a statement. "Security professionals need to remain cognizant of the regulations that their organizations must comply with and ensure they are taking steps to properly report the security incidents that are required by law -- whatever they may be."