The novelty coins are simple, gleaming expressions of support for former President Donald J. Trump. They’re also one of the hottest products on the market.

There’s a style for everyone, and each one includes a portrait of Mr. Trump. He’s sometimes rendered in gold, gazing thoughtfully into the distance. In others, he’s smirking in silver, giving a thumbs up, or riding a missile with a bald eagle flying behind him.

One version stands out among the others. It has become a favorite of right-wing social media and fringe news sites, and is simply known as the “Trump coin” online. It’s promoted alongside claims of stolen elections and conspiracy theories about global cabals. Some advertisements even refer to the coin as a type of cryptocurrency, implying that it will soon be worth thousands. Mr. Trump’s face is embossed in gold on a base of gleaming silver on the coin itself. “Keep America Great” is written in an arc above his head.

It could be yours for the low price of $0. (Additionally, shipping and handling is $9.99.)

This particular version has become a bit of an internet enigma. It’s unclear who is promoting or profiting from it. It is being sold by a mysterious news website about which little is known. The coin has nothing to do with Mr. Trump. There is no identifiable company taking credit.

Some internet sleuths have tracked down the organizations responsible for the coin’s popularity by following digital bread crumbs. The New York Times took a similar approach, following a network of advertisers from public storefronts to private marketing portals. Using insiders and marketing veterans as guides, the search crisscrossed the globe, implicating a handful of companies and a legion of anonymous marketers operating in uncharted territory.

Not only did the coin’s unusual origins become clear, but so did an entire disinformation supply chain that relied on falsehoods and misinformation at nearly every step. The coin’s success was fueled by fake social media accounts that promoted false advertisements and a slew of deceptive news websites that preyed on partisan animosity.

When viewed in its entirety, the coin demonstrates what many watchdogs have long suspected: many of the untruths that Americans encounter online aren’t created by foreign actors seeking to sow division. They exist solely to assist someone, somewhere, in making a quick buck.

That phony account is just one of many on Telegram that use celebrity names and photos to promote Trump. There’s Ivanka Trump (over 100,000 followers at one point), Mel Gibson (over 140,000), Trump-era special prosecutor John H. Durham (over 210,000), Keanu Reeves, Senator Ted Cruz, and even John F. Kennedy Jr. (who died in 1999). Each account promotes its own brand of patriotism, anti-vaccine rhetoric, and claims that President Biden is unfit. Many posts falsely claimed that the coin’s value was about to surge, invoking the soaring price of cryptocurrencies like Bitcoin.

After the Jan. 6 attack on the Capitol, conservatives turned to Telegram as Facebook and Twitter cracked down on conspiratorial and violent content. Telegram, according to watchdogs, has far less moderation than rival social media platforms. Many of the bogus accounts have been active for months, and new ones are constantly appearing. Others, such as the fake account with Mr. Washington, have been disabled or labeled “scam” or “fake” by Telegram.

In one post, a fake account for Representative Marjorie Taylor Greene, a Republican from Georgia who is close to Mr. Trump, shared a fake story on a fake Fox News website about a fake tweet by a fake Elon Musk, falsely claiming that Tesla’s CEO would soon accept Trump coins as payment. Mr. Washington’s spokesman said he was unavailable for comment but confirmed that the account was bogus. Ms. Greene did not respond to comment requests.

Some Trump supporters seemed to connect with the idea that physical trinkets could rise in value like Bitcoin, swayed by stories of crypto-millionaires or the promise that Mr. Trump could one day declare it legal tender. There is a genuine Trump coin cryptocurrency, but it is unrelated to the physical coins.