The first indication of a possible breach came when email addresses that have been used by the company only internally started receiving spam emails.
The company then moved to check their systems and spotted the intrusion. Apparently some 50,000 of its customers have had their username and password combination compromised.
The company started notifying users of the breach almost immediately, and assured them that the compromised passwords "cannot be used by third parties due to masking procedures," and didn't urge them to change them.
But according to Eduard Kovacs, the company only encrypted and salted properly (512-bit encryption with salt) the passwords for accounts created after December 2013, when the website was relaunched.
"However, the passwords of those who signed up before this date were stored in the Statista database as MD5 hashes. As many experts will tell you, MD5 passwords can be easily cracked," he pointed out.
Currently the main problem and risk for affected users is that they will likely be receiving more spam and phishing emails, possibly even some impersonating Statista, so they should be extra careful when reviewing unsolicited emails.