With little still known about the novel coronavirus and its treatments, some shady websites are grabbing coronavirus-related URLs to push unproven products to consumers.

The Food and Drug Administration (FDA) has issued more than 20 warning letters since mid-May to websites selling unproven COVID-19 treatments. These online retailers are selling products like hydroxychloroquine, essential oils and alternative sanitizers that claim to treat COVID-19 or kill the virus on surfaces.

Some of these websites are using coronavirus-related URLs to game SEO and bring in more traffic. Two recent warning letters were sent to websites that did this, one using the since-removed URL www.chloroquineonline.com and another using several different addresses, including www.TruthAboutCoronavirus.com, to then direct searchers to its main website.

The FDA took action against these websites, requiring that they remove claims that certain products will treat COVID-19 and stop selling drugs like chloroquine for unapproved uses.

A recent analyst report from Babel Street, a data analytics platform, saw a spike in websites selling drugs like hydroxychloroquine with terms like “no prescription required” in March. With many new domains related to coronavirus or potential treatments popping up.

“Some of the COVID-19 associated URLs continue to use hijacked root domains for obfuscation and redirection; however, several sites have begun to include the specific COVID-19 related drug names in the root domain name,” analyst wrote. “These URLs are new sites created to sell these newly popular drugs online. For example, domain analysis in Babel X shows that https://hydroxychloroquinesale.com, was created on 10 April 2020 and https://plaquenil200.com was created on 21 March 2020.”

According to Babel Street, these websites declined in April, perhaps because of enforcement actions from the FDA or supply chain issues, but began increasing again in May.

Other warning letters have gone out to websites selling misleading “solutions” or essential oils to treat COVID-19. The retailer behind www.TruthAboutCoronavirus.com, mentioned above, was claiming its “Nano-Silver Liquid” could prevent coronavirus.

In a letter sent on Monday, the FDA demanded an essential oil retailer remove mentions of coronavirus from its website. This seller didn’t specifically mention COVID-19, according to the warning letter, but the FDA clearly thought it was misleading nonetheless.

“It has potent antiviral properties and is a powerful antibiotic, particularly for RNA viruses, like the coronavirus responsible for acute respiratory syndromes,” the essential oil seller claimed.

The FDA is now compiling a steadily growing list of companies and domains selling fraudulent COVID-19 products.

“Shadow online pharmacies remain active and seek to exploit the COVID-19 pandemic for financial gain,” the Babel Street analyst concluded. “Consumers need to be wary and pay heed to the red flags of shadow pharmacies lest they be financially bilked and subjected to potentially ineffective or dangerous drugs.”