Global police body Interpol has warned of an "alarming" rate of cybercrime during the coronavirus pandemic, with criminals taking advantage of people working from home to target major institutions.
An assessment by the France-based organisation found a "significant target shift" by criminals from individuals and small businesses to major corporations, governments and critical infrastructure.
"Cybercriminals are developing and boosting their attacks at an alarming pace, exploiting the fear and uncertainty caused by the unstable social and economic situation created by Covid-19," Interpol Secretary General Juergen Stock said.
"The increased online dependency for people around the world is also creating new opportunities, with many businesses and individuals not ensuring their cyberdefences are up to date," he added.
The report said cybercriminals were sending Covid-19 themed phishing emails - which seek to obtain confidential data from users - often impersonating government and health authorities.
Cybercriminals are increasingly using disruptive malware against critical infrastructure and healthcare institutions, it added.
In the first two weeks of April 2020, there was a rise in ramsomware attacks, in which users have to pay money to get their computer to work again.
There was also an increase in the spread of fake news and misinformation which sometimes itself conceals malware, said Interpol.
From January to April, some 907,000 spam messages, 737 incidents related to malware and 48,000 malicious URLs - all related to Covid-19 were detected by one of Interpol's private sector partners, it said.
The agency warned the trend was set to continue and a "further increase in cybercrime is highly likely in the near future".
"Vulnerabilities related to working from home and the potential for increased financial benefit will see cybercriminals continue to ramp up their activities and develop more advanced and sophisticated" methods, it said.
Once a Covid-19 vaccine becomes available, Interpol said: "It is highly probable that there will be another spike in phishing related to these medical products as well as network intrusion and cyberattacks to steal data."