Security researchers disclosed that Ledger received warnings of potential hardware implants as early as December 2025, several months prior to the October 9 incident involving stolen cryptocurrency and modified devices sold through an authorized reseller.
Security researcher Joe Grand notified Ledger on March 4, 2026, about a malicious implant found in a Ledger Nano X purchased in August 2025. Former Mt. Gox CEO Mark Karpelès identified at least two people who had contacted Ledger about suspected device tampering, including Vietnamese cryptocurrency educator Tai Zen's report in December 2025. The disclosures raise questions about whether earlier incidents could have prompted stronger customer warnings or additional security measures. Independent blockchain investigators estimate suspected losses between $86 million and $93 million. On October 15, Ledger stated the incident was a localized distribution attack and announced tighter controls requiring authorized sellers to prohibit returns of previously sold devices to inventory, store products away from public shelves, and promptly report unusual complaints.