Crypto Hackers Stole More Than $17 Billion Over Past Decade, DefiLlama Says

Crypto assets are controlled through private keys. If those keys are stolen through phishing, malware or compromised signing procedures, attackers can transfer funds directly. DefiLlama data covering security incidents from around 2016 to 2026 puts cumulative losses at more than $17 billion, underscoring how the main threat has expanded beyond smart-contract flaws to wallet and key management.

Data available as of 2026 shows that private-key compromises accounted for about 40% of $16 billion in hacking losses, with phishing also a major attack vector. The Kelp DAO cross-chain bridge was recently attacked again in what became the largest crypto theft of 2026 to date, highlighting the continued risks surrounding cross-chain signing and asset-custody infrastructure.