New figures reveal that £60.4 million was lost to online banking fraud in the UK alone last year, a rise of nearly £20 million over 2013.
The sharp rise of 48% has caused the Financial Fraud Action UK agency to renew its warnings.
It says that people should install the best security and anti-virus software on their computers and never open any suspicious emails or links.
Conmen, ever keen to swindle money, are changing tactics. Scams are increasing in which people are being urged to reveal personal details such as dates of birth, pin numbers and passwords.
Fraudsters have been finding that telephone calls have been successful. Posing as bank or police officials has shown that many people release financial details and even transfer their money into the fraudster's account.
The advice is to hang up on any such cold call and report the matter to the bank.
Businesses are more frequently target now as well as individuals.
The number of online banking fraud loss cases last year in Britain was 53,192, which FFA UK said is still "relatively modest" given that about 26.9 million people in the UK now use online banking.
