Investing.com — Cryptocurrency hardware wallet maker Ledger is investigating an attack involving modified devices containing hidden surveillance components, with estimated losses exceeding $90 million.

The investigation has focused on Malaysian cryptocurrency retailer CryptoBilis, where customers began reporting missing funds on October 9. Blockchain researchers estimate that more than $90 million in digital assets has been stolen.

Ledger, the Paris-based manufacturer, said an organised criminal group had installed concealed hardware inside some of its wallets.

The company is also investigating reports of compromised devices purchased elsewhere, raising concerns that the attack may extend beyond…