Hackers reportedly stole 42 million customer records including email addresses and clear-text passwords from Cupid Media, a network of dating websites.
A file containing the Cupid Media user data was found on the same server where hackers also stored millions of records stolen from Adobe, PR Newswire, the U.S. National White Collar Crime Center (NW3C) and other organizations, independent security journalist Brian Krebs reported.
According to Krebs, who claims to have access to the data, the database contains names, email addresses, plaintext passwords and birth dates.
Based in Southport, Australia, Cupid Media operates a network of more than 30 niche online dating websites with more than 30 million members in North and South America, Europe, Asia Pacific and the Middle East.
Andrew Bolton, Cupid Media's managing director, told Krebs that the information found on the rogue server appears to be related to a security breach that happened in January 2013, which customers had been notified about.
Bolton also reportedly said that a large portion of the leaked records correspond to old, inactive or deleted accounts and that the number of active users actually affected by the breach is considerably less than 42 million.
Cupid Media didn't immediately respond to a request for comment sent Wednesday.
According to Bolton, the company is now double-checking to make sure all affected users had their passwords reset and were notified by email.
After the January breach the company hired external consultants and implemented several security measures, including password hashing and salting, he said.
Storing cryptographic representations of passwords, known as hashes, instead of their clear text versions has long been a security best practice. However, as this breach shows, some website owners fail to implement the measure.
"Many companies shy away from encryption due to fear that it will be either too expensive or complicated, however the reality is that it doesn't have to be either," Jason Hart, vice president of cloud solutions at security company SafeNet, said via email. "With hacking attempts becoming almost a daily occurrence, it's clear that being breached is not a question of if but when."
Encryption and hashing -- both cryptographic functions -- can be used to protect data from attackers in case of a security breach, but only if implemented correctly.
A recent data breach at Adobe exposed 150 million user names and encrypted passwords. However, according to security researchers Adobe used encryption in an insecure way, making many of the passwords recoverable.
Last year, 6.5 million password hashes corresponding to LinkedIn accounts were posted in an underground forum. More than 60 percent of those hashes were cracked using brute-force methods because LinkedIn used a weak cryptographic hash function called SHA-1 without salting -- a measure that strengthens hashing.