Many insurance companies in Hong Kong offer professional liability products, which may protect enterprises from some forms of data loss due to failure in computers or infrastructure, according to Stella Tse, Asia Leader for the Financial and Professional Risks Practice at insurance firm Marsh Hong Kong -- an insurance brokerage firm that has provided cyber insurance coverage since 2000.

"Many banks and financial institutions are protected from data losses due to computer failure through the professional liability and computer crime coverage," said Tse. "Although it may overlap existing insurance coverage, cyber insurance can sometimes provide additional coverage over-and-above the existing policies."

She added most existing insurance policies cover outages caused by property-based or physical damage, meaning that damages due to data loss remain a grey area.

One major difference between cyber insurance and existing professional liability policies is business interruptions caused by security breaches. But enterprises must also be aware of the fine print in their policies.