“Yesterday was not a good day for Novartis,” Narasimhan wrote to employees Thursday in a letter reviewed by Bloomberg News. A day earlier, the drug company said it had paid $1.2 million to a firm led by Cohen, who is at the center of a U.S. law enforcement probe, as well as a civil lawsuit related to payments to an exotic dancer.

“We made a mistake in entering into this engagement and, as a consequence are being criticized by a world that expects more from us,” Narasimhan said in the letter. “What defines us now is how we respond to this difficult situation.”

Novartis hired Cohen’s company in 2017. The company said it quickly determined that the lawyer’s firm would be unable to provide the services it anticipated and decided not to engage further, but was contractually bound to keep making monthly payments of $100,000.

While Novartis said it got little from Cohen, the arrangement dragged Novartis (NVS) into Special Counsel Robert Mueller’s probe into suspected Russian meddling in the U.S. presidential election. The company said it was contacted by Mueller’s office in November, though now considers its role in that inquiry closed.

The latest developments come just as the company seeks to move beyond a string of legal troubles and its new CEO looks to reshape the company’s culture and reputation. Separately, AT&T (T) paid Cohen up to $600,000 for insights and asked him to look into its proposed $85 billion merger with Time Warner (TWX) as it sought government antitrust approval, according to a person familiar with the matter.

Novartis shares fell 0.5% in early trading in Zurich, having dropped 6% this year.

Narasimhan, a 13-year company veteran, took the helm earlier this year, replacing Joe Jimenez. He said in his letter that he went to sleep “frustrated and tired” and woke up “full of determination.”

“I look to you to remain resilient and keep your focus on serving patients,” he said.