A report says the shift to home working has exposed the country's vulnerability to cyber crime.
Conning people out of as little as £10 on a mass scale has become the new tactic by cyber fraudsters who are taking advantage of people now working from home during the pandemic.
A Royal United Services Institute (RUSI) think-tank paper said a phenomenon dubbed "silent stealing" has begun as criminals are "going down market" from big money scams.
Individual victims are less likely to report the loss of a small sum of money, while it is difficult for police and banks to know whether they are dealing with a single fraud or a big criminal operation worth millions of pounds, according to the research.
"There's a working hypothesis that criminals are going down market," the report says.
"Yes, trying to steal £10m from a bank is an option, but stealing £10 a hundred thousand times is going to give you a good return and probably go below the radar.
"Are you going to call Action Fraud or your bank in the case where you lose £10?"
Sneha Dawda, one of the authors, said silent stealing has become so popular because the high level of breached data available online makes it easy for criminals to buy people's personal details and use them for fraud.
She warned people to be careful what they share online, with fraudsters employing social engineering techniques, which use that information to craft personal phishing emails to trick recipients into handing over their details.
"It's probably down to a lot of awareness of the individual that they can identify a phishing email when they see one, that they double check before they click on links, that they don't enter their login details when they're even remotely suspicious that it's not secure," she said.
"It's really about checking, checking and checking again before you do anything like giving out your details because cyber breaches are constantly happening, they expose a lot of information and simple things like a password manager and having unique secure passwords for each account that you have will minimise that risk of cyber criminals being able to take advantage of multiple accounts."
RUSI last month warned fraud has reached "epidemic levels" and called for the crime to be prioritised as a national security issue with a greater role for the intelligence services.
Its latest report, entitled The UK's Response To Cyber Fraud: A Strategic Vision, said cyber fraud in the UK "is rampant, costing millions of pounds and leaving victims in its wake".
The authors said the COVID
-19 pandemic and the shift to home working has exposed the country's vulnerability to the crime.