Cryptocurrency hardware wallet manufacturer Trezor issued a warning to users Nov. 19 after making what it called the “startling” discovery that rogue actors were creating and selling fake devices.

Trezor, which together with Ledger and KeepKey forms one of the oldest and best-known wallet manufacturers, said that an “unknown” third party was distributing “one-to-one copies” of its flagship Trezor One device.

“Trezor clones have been released over the years of our activity,” officials said, noting:

“However, in recent weeks, we have discovered something more startling. A one-to-one copy of Trezor One. In other words, a fake Trezor device, manufactured by a different, unknown vendor.”

The latest move to impersonate aspects of the cryptocurrency sphere, the fake appears not unlike the many social media heists offering fraudulent free tokens and endorsements under the name of other well-known figures from the industry.

Scammers have even targeted Initial Coin Offerings (ICO) with fake versions in order to steal funds from would-be contributors.

The Trezor One case involves subtle differences in packaging, Trezor says, confined to areas such as the hologram and barcode sticker.

Seeming to originate from China, the company wrote that users should exercise suspicion when purchasing devices over the Internet from third parties.

“Be very cautious when buying on other marketplaces, such as eBay, Taobao, AliExpress, unknown Amazon resellers or other places,” it added, stating: