That’s the warning from the National Cyber Security Centre in a report Tuesday to mark the start of a conference it’s hosting.

In one case believed to set a legal precedent, lawyers for a UK businessman issued an injunction against “persons unknown” after false and doctored stories were shared on social media, the NCSC said.

Among the fastest-growing areas of fraud is the tactic of impersonating a company’s chief executive officer or senior official to coerce an employee, customer or vendor into transferring funds or sensitive information, according to the report. More sophisticated technology and cheaper costs make the strategy more effective than traditional ransomware.

Meanwhile, newer techniques for mining cryptocurrencies are also on the rise, led by so-called cryptojacking, which exploits visitors to a website to mine the currencies without their consent, the center said.

Security of data stored in the cloud “will become a tempting target for a range of cyber criminals,” the NCSC said, as currently only 40% of data stored there is access-secured.

Too much faith is placed in cloud providers by customers who don’t stipulate how data should be stored, the report found.