(Reuters) – Under Armor Inc. ( UAA.N ) ( UA.N ) said Thursday that data from approximately 150 million MyFitnessPal diet and fitness App accounts were compromised in February, in one of the biggest hacks in history, stocks of sportswear manufacturers send 3 percent in after-hours trading.
The stolen data included account usernames, email addresses, and encrypted passwords for the popular MyFitnessPal mobile app and website, Under Armor said in a statement. Social security numbers, license numbers and payment card data had not been compromised, it said.
According to SecurityScorecard, this is the biggest data breach this year and one of the top 5 so far, based on the number of compromised records.
Larger hacks include 3 billion Yahoo accounts compromised in a 2013 incident and credentials for more than 412 million adult website users operated by the California FriendFinder Networks Inc in 2016, according to the privacy statement LeakedSource.com.
Under Armor said it collaborated with data security firms and law enforcement agencies, but did not provide details on how hackers would invade their network or extract their data without being caught.
While the breach did not include financial data, large amounts of stolen e-mail addresses can be valuable to cybercriminals.
E-mail addresses retrieved during an attack in 2014, affecting data from 83 million JPMorgan Chase customers, were later used in pump-and-dump systems to boost stock prices, according to US federal accusations 2015.
Under Armor said in a warning on his website that MyFitnessPal users need to change their passwords, and urged users to do so immediately.
"We continue to monitor suspicious activity and coordinate with law enforcement agencies," the company said, adding that it strengthens systems that detect and prevent unauthorized access to user information.
Under Armor said that on Thursday, four days after it learned of the incident for the first time, it began informing users about the violation.
Under Armor bought MyFitnessPal in 2015 for $ 475 million. It is part of the affiliate fitness department of the company, whose sales last year accounted for 1.8 percent of Under Armor's total revenue of $ 5 billion.
(This story has been corrected to correct Nivedita Balu instead of Nivedita Bhattacharjee)
Nivedita Balu reporting in Bengaluru and Jim Finkle in Toronto; Edited by Leslie Adler