The automated phone systems and website of lender and servicer Mr. Cooper are running again following a cybersecurity incident that forced the company to lock down certain technology systems.

On Oct. 31, the company suffered a cyberattack that disrupted loan payments. Mr. Cooper restarted servicing operations on Nov. 4 by taking customer calls and payments, remitting to investors and onboarding new loans.

Mr. Cooper’s investigations into the cyberattack are still ongoing, but the company believes that certain customer data was exposed. Mr. Cooper had 4.3 million customers by the end of Sept. 30.

“We are continuing to investigate precisely what information was exposed. In the coming weeks, we will mail notices to any affected customer and provide them with complimentary credit monitoring services,” Mr. Cooper said on its website.

Mr. Cooper advises customers to report any unusual activity to their financial institution and update their passwords frequently to prevent any potential fraud.

Customers had hammered its social media accounts with complaints of not being able to get a confirmation after making a large mortgage payment. 

As long as customers make their payments by the end of November, no late fees or penalties will incur, the company said.

In an 8-K filing, Mr. Cooper said it does not believe this incident will have a material adverse effect on its business, operations or financial results.

Mr. Cooper delivered $275 million in net income in the third quarter, compared to $142 million in the second quarter.

Operational impacts will be limited to the fourth quarter, according to the company.