Under Armour Inc., joining a growing list of corporate victims of hacker attacks, said about 150 million user accounts for its MyFitnessPal nutrition tracker were breached earlier this year.

An unauthorized party stole data from the accounts in late February, Under Armour said on Thursday. It became aware of the breach earlier this week and took steps to alert users about the incident, the company said.

The data didn’t include government-issued identifiers, including Social Security numbers and driver’s license numbers, Under Armour said.

Shares of Under Armour fell 2.6 percent to $15.93 in late trading following the announcement.