Companies have been urged to take care online in a talk by police for Humber Business Week.
Speaking to an audience at the KC Stadium in Hull, Humberside Police and Crime Commissioner Matthew Grove said cyber crime was an increasing problem.
He warned firms they had to work to protect their assets and prevent fraud or theft.
Mr Grove also called on businesses to contact the police if they had any concerns about crime near their premises.
He said: "The criminals who carry out these types of crimes are developing evermore sophisticated ways of breaking into your business.
"For certain crimes we can't rely solely on the police. Businesses must help themselves first.
"Without security, our businesses are vulnerable from anywhere in the world."
The commissioner's fears were echoed by a senior police officer.
Detective Chief Superintendent Phil Walker, the force's head of crime management, warned the audience to take steps to stay safe.
He said many firms suffered from lax security online that could be easily exploited by hackers and other criminals.
DCS Walker said: "Ensure your computer systems are properly configured. Choose strong passwords – make sure you've got a mixture of letters, numbers and symbols with upper cases and lower cases.
"The recommendation is you change it every 90 days or so."
Visit www.bcrc-uk.org or www.police.uk for business crime prevention advice. Visit www.actionfraud.police.uk to report fraud.
