British authorities estimated that £34.5 million ($68 million) has been stolenin Covid-related fraud and cyber-crime in the past year in the UK.
There have been cases around the globe of fake tests, protective gear and vaccines.
And also profiteering on real jabs.
The BBC reported that people were paying between US$500 and US$750 ($715-$1075) to get authorised doses unavailable to them.
Now security experts are particularly watching trends over fake proof of vaccination. The BBC said some fake vaccination certificates are being sold for US$150 ($215).
With vaccine rollouts under way in different countries, vaccine passports and certificates are the new targets as people anticipate travelling again.
Covid passports will eventually be New Zealanders' gateway to tourist travel without quarantine.
People in places overseas are already being required to produce proof of tests or vaccinations at some event venues and for international travel.
The real-world evidence of vaccine protection is increasingly positive, although vaccine rollouts are battling to get ahead of the spread of new variants and Covid case spikes are occurring.
Scientists expect modified booster shots will be needed as early as next year.
Still, this week the director of the US CDC, Dr Rochelle Walensky, said of transmission: "Our data suggest that vaccinated people do not carry the virus".
Some people, still hesitant about getting a jab, may prefer the appearance of vaccination to actually going through with it. One ad on the dark web offered a "vaccination certificate for Covid (for those who do not want to be vaccinated)".
Ekram Ahmed of cybersecurity firm Check Point told ABC News: "Cyber criminals are looking to capitalise on the public's interest to get the vaccine or avoid the vaccine. It's only a matter of time before hackers find a way to organise fraudulent activity for digital passports."
Countries planning to use Covid digital passports via a mobile app include the United States, European Union members, China, and Japan.
In New Zealand there's also been a specific interest in whether pre-departure tests results are always genuine or not.
Since mid-January, people landing here from most countries have had to prove they had a negative test before their flight.
There have been doubts about how useful such tests are considering people can get infected in transit.
Covid scams are widespread because so many people are desperate to get a vaccine or get access to something they want that a jab or a test provides, such as escape from the fear of infection or the green light to head home.
In countries where Covid-19 infection rates are high, vaccination queue-jumping remains a concern.
Authorities' mishandling of the pandemic response last year, slow vaccine rollouts, rows over supplies of shots, and the hoarding of doses have given opportunists openings worldwide.
This year is a definite improvement on the utter shambles of 2020, but the world's recovery from the pandemic is likely to be slower than it needed to be.
More cooperation and coordination over vaccine production and distribution obviously would have speeded up the process. The fact that governments are still scrapping over supplies is a surprise to no one.
Any fraudulent behaviour in a pandemic jeopardises us all. The potential for the virus to slip the net is only heightened by such misdeeds. It is in all of our interests to be alert and sound the alarm on anything suspect.