private-key

The Blockchain Bandit is an unidentified threat actor or group that systematically exploited Ethereum wallets holding cryptographically weak private keys between approximately 2015 and 2018, accumulating more than 45,000 ETH (worth over $54 million at peak 2018 valuations) through a technique researchers later termed 'Ethercombing.' The actor compromised 732 private keys across 49,060 transactions, draining wallets in near-real-time using automated blockchain monitoring. Dormant since 2018, the actor re-emerged in January 2023 and again in December 2024, consolidating approximately 51,000 ETH (valued at roughly $172 million) into a single multisig wallet, as tracked by on-chain investigator ZachXBT.

Nexera (formerly AllianceBlock) is a blockchain infrastructure protocol focused on compliant real-world asset tokenization, operating primarily on Ethereum. In August 2024, a threat actor later attributed to North Korea's Lazarus Group used social engineering and BeaverTail malware to steal smart contract management credentials, enabling unauthorized transfer of 47.24 million NXRA tokens valued at approximately $1.9 million. The team mitigated further losses by zeroing out and subsequently burning the 32.5 million tokens that remained in the attacker's wallet, limiting confirmed liquidated losses to roughly $449,000.