Ransomware is malicious software that prevents you from accessing your computer, or accessing data that is stored on your computer.
If your computer is infected with ransomware, the computer itself may become locked, or the data on it might be stolen, deleted or encrypted.
Normally you're asked to make a payment - the ransom - in order to 'unlock' your computer or data.
South Yorkshire Police’s Cyber Protect Officer Dannielle Lee works with local businesses, charities and other organisations said ransomware attacks can have a devastating impact on organisations.
In such cases, she explained, victims often require a significant amount of recovery time to re-enable critical services.
She said: "The average cost of a cyber attack to a small business is around £11,000 and unfortunately there are thousands of successful attacks nationwide every day.
"Luckily, there are a number of things you can do to reduce your business's chances of becoming a victim.
"One of those is to sign up to a free tool called Police CyberAlarm, which acts like a 'CCTV camera' to monitor the traffic seen by a business's connection to the internet.
"I'd highly recommend this for organisations across South Yorkshire."
Businesses can sign up for a Police CyberAlarm on the cyberalarm.police.uk/#join website.
If your business, charity or other organisation and think you have been a victim of a cyber attack, report it to Action Fraud online at www.actionfraud.police.uk or by calling 0300 123 2040.
For live cyber attack (in progress), call 0300 123 2040 immediately.