A north Norfolk computer shop owner is sending out a warning to local traders, after discovering that dozens of the area's businesses and organisations have been the victims of data breaches, potentially leaving them open to attacks by cyber criminals.

Eastern Daily Press: Sheringham town centre, where computer shop owner Clive Sanham says 45 businesses have been subject to online date breaches.Photo: KAREN BETHELLSheringham town centre, where computer shop owner Clive Sanham says 45 businesses have been subject to online date breaches.Photo: KAREN BETHELL (Image: Archant)

Clive Sanham, of PC Simple, in Sheringham, says new software he has bought gives him access to advanced security tools allowing him to obtain details of email accounts that have been compromised, and is urging small and medium business owners not to ignore the threat of online attacks.

'We know that a huge percentage of all crime is committed online and there are new threats every day,' Mr Sanham said.

His investigations led him to discover that the email addresses and passwords of north Norfolk solicitors, accountants, cafes, shops and local government employees could be easily accessed, with 45 identified in Sheringham alone.

'What this means is that if someone has your email address and password, they can then use this to access your other accounts, and that could lead to big problems,' he said.

Businesses and individuals also often received 'phishing' messages sent from their own email addresses, Mr Sanham added, with these including links which, once clicked on, could download malicious software or give the sender access to sensitive information.

'Sometimes these emails seem very credible and when you click on the link, you are sent to a seemingly genuine website but, before you know it, they've got your bank details,' he explained.

PC Simple business to business manager Josh Allman said he was shocked to discover the number of account breaches.

'I don't think people realise how easy it is to carry out an attack,' he said. 'Breaches often go undetected for up to 12 months and, when that breach is disclosed, businesses can lose credibility with their customers.'

Mr Sanham, who says he has had customers who have lost up to £7,000 as a result of cybercrime, is now working with Sheringham Chamber of Trade to raise awareness of the issue and will be teaming up with police officer Ian Smith, who is beat manager for Sheringham, to run a cyber security seminar on behalf of North Norfolk District Council on April 24.

'We don't want to scare people, but I think businesses need to wake up to the threat and make sure they stay secure,' he said.

How to protect yourself, or your business from cybercrime: the dos and don'ts of staying safe online.

Use strong passwords and change them regularly: Have different passwords for different accounts and use a combination of numbers, letters and symbols.

Update software: Make sure you install operating system and software updates.

Avoid clicking on links in emails, even if the sender appears to be genuine: Always type a website address directly into your browser bar rather than following a link, which could lead you to a fake website or download malicious software onto you computer.

Install paid-for security software to protect your computer from malware, viruses and ransomware (which can shut down your machine until you pay a 'ransom').

Do not respond to phone calls asking you to make changes to your computer. Companies such as Microsoft and Google do not contact customers by telephone. If you are unsure, put the phone down immediately. If you are concerned, contact the company directly.

Manage your social media settings: Make sure your profile is set to private and don't reveal personal information such as email addresses and phone numbers online.