Six Bitstamp employees were targeted in a sophisticated weeks-long phishing campaign starting in November 2014. The attacker sent social engineering emails to the CTO and system administrator, culminating in malware installation that gave the attacker access to the exchange's hot wallet infrastructure.

Bitstamp reported that multiple operating wallets were damaged, resulting in the loss of 19,000 bitcoins. The company was hacked by multiple phishing attacks in the months before the attack. An employee downloaded a malicious file that allowed an attacker to access the password of the company's hot wallet and the server including the wallet.dat file.