Over 9 million AT&T customers have been notified of a data breach exposing their data shared with the company. Those that use its services have likely received an alert detailing the attack. We recommend checking your inbox to see if you’ve gotten the message.

Here’s what you need to know if you’ve been affected.

According to AT&T’s data breach notification, the problem began when a third-party marketing vendor was attacked by hackers earlier this year. Fortunately, much of the data procured through the breach appears only to include customers’ business with AT&T. 

Data in the breach includes first names, wireless account numbers, phone numbers and email addresses.

While the personal data exposed may seem tame compared to other data disasters, it’s worth mentioning that information of this nature could lead to a stolen identity. The brand promises that if any customer information is found on the Dark Web, the affected party will be notified immediately.

AT&T is urging you to be responsive to security alerts coming from the defensive measures it has in place. The company also asks that anybody impacted be on the lookout for suspicious phishing messages and change their passwords immediately, just in case.

Sound like a tech pro, even if you’re not! Award-winning popular host Kim Komando is your secret weapon. Listen on 425+ radio stations or get the podcast. And join over 400,000 people who get her free 5-minute daily email newsletter.

Data breaches don’t end with the breach. Cybercriminals will pursue other avenues to exploit the situation. Whenever there is a massive data breach, taking action is critical. Here are some things to do following a data breach: