Lots of ways: - Software you use for key generation uses a known random-seed. - Compromised software that converts your seed into an address/priv key. - Comp

Lots of ways: - Software you use for key generation uses a known random-seed. - Compromised software that converts your seed into an address/priv key. - Compromised transaction generation software. - Offline wallet physically stolen - Malware / firmware exploit on USB used to transfer transactions between online & offline computers