Burrito chain Chipotle is just beginning to rebound after a number of high-profile food borne illnesses, but last night the company revealed a bit of not-great news: Its payment system was hacked for several weeks.

During a conference call to discuss Chipotle’s latest quarterly earnings, chief financial officer Jack Hartung revealed that the company recently learned of unauthorized activity on the network supporting its payment processing systems between March 24 and April 18.

Hartung said the company immediately began an investigation into the activity and believes those actions — which included working with cyber security firms, law enforcement, and the payment processor — stopped the activity.

“Because our investigation is continuing, complete findings are not available, it’s too early to provide further details on the investigation,” Hartung said.

As a result the company did not provide additional information such as how many and which restaurants were affected, or what customer information may have been acquired by the supposed hackers.

The company, which has implemented unspecified additional security enhancements since uncovering the activity, says it will notify any customers affected by the breach as it learns more about specific timeframes and the restaurant locations that might have been compromised.

In other earnings call news from Chipotle:

• The company announced that its revenue has begun to bounce back after its issues with foodborne illnesses, increasing 28.1% to $1.07 billion for the first quarter of 2017 compared to its levels in the first quarter of 2016.

As for same-store sales, Chipotle reported a 17.8% increase for the first quarter. The increase, the company said, was driven to some extent by new restaurant openings and closings. In all, Chipotle opened 57 new restaurants and closed its 15 ShopHouse Southeast Asian Kitchen restaurants.

• The company also provided more information on its long teased dessert offering.

In fact, CEO Steve Ells says Chipotle is developing two desserts, the first of which will begin testing at select stores this month.

Described by Ells as a traditional Mexican dessert, buñuelos is a fried tortilla strip with honey, cinnamon, and sugar and will be served with an apple caramel butter dipping sauce.

“Buñuelos are simple to make using our existing equipment and require us to add just a few additional ingredients,” Ells said. “They’re delicious and complement our menu nicely.”

Ells did not provide details on when the dessert would begin tests or where they would take place.