Why hackers are targeting the world's shipping

Defending against GPS jamming and spoofing is difficult and expensive, but "anti-jam" technology is available.

Meanwhile, another weakness for cargo ships is the increased use of sensors to monitor their emissions. These often transmit the data, so offer hackers another possible line of entry and attack.

The good news is that the industry is working to tighten up security. In 2021, the International Maritime Organization (IMO) regulator added new cyber security provisions to its global safety management code for merchant shipping.

"These provisions brought into law more specific cyber risk management requirements to be incorporated into the ship safety management system, to address deliberate cyber-attacks, and to prescribe risk management practices into the operation of compliant merchant ships," explains Tom Walters, another shipping specialist at HFW.

Ship management systems are now required - rather than simply advised - to include increasingly stringent cyber security measures, ranging from basic security hygiene to more technical operational and IT measures.

"Personally, I think the industry is in a good place to deal with the threat - certainly compared with six or seven years ago," says Mr Stawpert.

"There's hugely increased awareness across the industry of cyber attacks and cyber crime, and that will increase over the coming years."

Back at law firm HFW, how exactly do they communicate with the criminal gangs? Henry Clack says it is via electronic text, and kept as brief as possible.

"When it does happen, it is more often than not in the context of ransomware ransom negotiations. Communication is via online messaging services, maybe one message, no more than a couple of sentences, each day."