Dark web drug dealers have turned to selling face masks and unregistered testing kits amid the Covid-19 pandemic.
Experts from security firm Digital Shadows have seen accounts better known for peddling illegal substances expand their range in a bid to cash in on rocketing global demand.
They have also seen sellers offering discounts apparently to help entice people stuck in lockdown to buy drugs online.
Threat research analyst Alex Guirakhoo said: “Cyber criminals who typically engage in the sale of illicit drugs have seen the opportunity to diversify their listings to include sales of face masks, hand sanitiser, and now even chloroquine on popular cyber criminal marketplaces like Empire.
“For those vendors not involved in the sale of personal protective equipment (PPE), Covid-19-related terms have also been used to promote their drug sales.
“This is likely an attempt to keep their businesses going and attract customers who have been financially impacted by the pandemic.
“It is also realistically possible that cyber criminals are attempting to capitalise on customers impacted by shelter in place orders.
“If people cannot physically meet their dealers, they may be more enticed to purchase drugs on the dark web.”
Dealers are disguising themselves as key workers to try to avoid detection when out on the street.
Warnings have also been issued over an increased risk of fraud as more people shop online during lockdown.
Digital Shadows analysts have seen users of Russian and English language forums pondering how to cash in, with one asking: “Who thinks what about this? How to get the maximum benefit from quarantine? It will not be forever.”
Earlier this week, the NCA warned that there had been £1.8 million of fraud linked to the pandemic.
It has shut down six domains since the outbreak of the virus to stop cyber attackers trying to steal personal data.
Investigators also took down a website trying to lure customers into buying non-existent PPE, and arrested two men on suspicion of illegally selling Covid-19 testing kits and making false claims about their efficacy.