BUSINESSES could leave themselves open to cyber attacks as they make changes to their supply chains after Brexit, a cyber security expert has warned.

Matt Horan, security director with Poole-based C3IA Solutions, said it was important for firms to ensure any new elements in their supply chain were secure.

He said some companies might be so keen to organise different suppliers that they left themselves vulnerable.

One weak spot in a supply chain can have knock-on affects for all the other businesses involved.

Mr Horan, a former Royal Signaller who works in the public and private sectors, said: “This is a serious issue that could massively impact on business.

“Whatever happens with regard to Brexit, businesses are now correctly working to mitigate against supply problems, especially if a so-called ‘no deal’ exit occurs.

“Companies obviously want to ensure their work is unhindered and this has led in some cases to stockpiling and also to lining up new suppliers – possibly from outside the EU.

“While these transitions might maintain an effective supply chain it is imperative that security is not overlooked.

“We have seen the results of breaches in supply chains and one weakness can have major repercussions; if you drop a stone in a pond the ripples will travel right to the periphery.

“Existing supply chains might have been built up over years with special regard made to information assurance and security. But when putting links together in haste this is one aspect that might not have the priority it ought to.”

In serious cases, an attack could affect the national economy as well as proving disastrous for the businesses involved, he said.

He added: “Whether the motive is financial – through ransomware for example – purely malicious, political or due to industrial espionage, any weakness will be identified.”

The most famous ‘ransomware’ attack on computers was the WannaCry virus of May 2017, which reached around 200,000 computers and is estimated to have cost NHS trusts £5.9million.