On-chain Safety Education

Understand the chain.
Protect your wallet.

Onchain Diary is an independent Web3 safety education site: 120 deep-dive articles, a 232-term glossary, and the complete BIP-39 wordlist: covering crypto scams, smart contract security, and on-chain analysis. No jargon. No sign-up. No tools to install. Just the knowledge you need to stop getting rekt.

120 Articles
232 Glossary Terms
0 Sign-ups Required

Latest

Guides, tutorials, and deep dives.

The Task Scammer Who Lost 60 BTC to a Tampered Ledger Wallet

Chainalysis says one of the biggest Ledger theft victims was a task-scam operator — 60 BTC of scam proceeds sat in three implanted hardware wallets for 17 days before being drained in a single morning.

Denmark CPR Breach: 8.8M Identities Sat Behind a '123456' Password

A hacker ran 14 million queries against Denmark's national register for ten days through a small IT firm whose admin account used the password 123456. What 8.8 million leaked identities mean for crypto users.

Ledger Implants Reach European Retail: Two MediaMarkt Devices, One 'Eurasian Version' Antenna

A buyer found hardware implants in two Ledger Nano X wallets bought at different MediaMarkt stores in Europe. Mark Karpelès identified the devices as carrying an earlier implant design — with an antenna labeled 'Eurasian version.' Within 48 hours, MediaMarktSaturn delisted Ledger group-wide, Ledger asked Southeast Asia and Hong Kong resellers to halt sales, and Bitquery's tally reached $102 million. Here is what is verified and what isn't.

Bitcoin Blackmail Emails Explained: The Password Is Real, the Video Is Not

An email shows an old password you actually used, claims malware recorded you through your webcam, and gives a Bitcoin address with a 48-hour countdown. Here is what on-chain research and FBI guidance say about these campaigns, the 2026 named-crew upgrade that adds real breach data, and exactly what to do in the first hour.

FMMR Mining Scam: A Fake Pool Farmed 151 Wallets for Over 1.5M USDC — and the Permits Are Still Live Until 2030

The fake 'FMMR Mining' pool farmed 151 wallets for over 1.5M USDC; every victim signed a 10M-USDC permit valid until 2030. Original domain fmmrvip.click is dead — fmmrvip.space is the same scam, registered the same day, now ranking on Google page one for its own name.

The Ledger–CryptoBilis Hack: How Buying a Trusted Reseller Became the Attack

An authorized Ledger reseller was secretly acquired, its devices implanted, and an estimated $72M–$90M drained from buyers. The full timeline of a textbook supply-chain takeover.

Don't transact blind.

Whether you're new to crypto or deep into DeFi, understanding how scams work is the best defense. Every guide here is free.

Start Reading →