The Federal Bureau of Investigation (FBI) has issued a public warning about fraudulent cryptocurrency apps, which have swindled U.S. investors out of an estimated $42.7 million so far.

According to an advisory published on July 18 by the securities and intelligence agency, cybercriminals have created apps using the same logos and identifying information as legitimate crypto companies to defraud investors. The FBI noted that 244 people had already fallen victim to these fake apps.

One case saw cyber criminals convincing victims to download an app that used the same logo as an actual U.S. financial institution, encouraging them to deposit cryptocurrency into wallets purportedly related to their accounts.

When victims attempted to withdraw from the app, they would be asked to pay taxes on their withdrawals. However, this was just another ruse to part more funds from victims, as even if they made the payments, the withdrawals would continue to be unavailable.

Around $3.7 million was defrauded from 28 victims between December 2021 and May 2022, said the FBI.

Another similar operation saw cybercriminals operating under the company name “YiBit”, defrauding at least four victims of around $5.5 million between October 2021 and May 2022, using a similar method of deceit.

A third case involved criminals operating under the name “Supay” in November 2021. They defrauded two victims by encouraging them to deposit cryptocurrency into their wallets on the app, which would then be frozen unless more funds were deposited.

Warnings about fraudulent apps have also made the rounds on crypto Twitter.

One user said a friend recently fell victim to a scam that started on the online messenger service Whatsapp which encouraged the victim to