Security company ADT disclosed in an SEC filing that hackers obtained “some limited customer information, including email addresses, phone numbers and postal addresses.” TechCrunch reports that ADT’s disclosure follows a seller on a cybercrime forum claiming last week that they had obtained more than 30,000 stolen ADT customer records.

The hackers obtained the information by accessing “certain databases containing ADT customer order information,” according to ADT. The company believes that only a “small percentage” of its subscribers were affected and says it has notified those customers. (ADT has about 6 million customers, according to a June blog post.) ADT says that it has “no reason to believe” that the hackers compromised home security systems and that credit card data and banking information wasn’t taken.

“Our customers’ privacy and security is our utmost priority, and we have taken several steps to help keep their information safe, including immediately activating rigorous cybersecurity protocols,” ADT spokesperson Ben Tamblyn says in a statement.