– Target’s chief financial officer will testify Wednesday on Capitol Hill for the first time since the company admitted it learned of suspicious activity in its computer system a month before one of the biggest data breaches in U.S. history.

CFO John Mulligan will testify at a Senate Commerce, Science and Transporation Committee hearing on guarding consumers against cyberattacks.

Mulligan appeared at earlier Senate and House hearings where he said Target first learned of suspicious activity from federal officials Dec. 12.

But Bloomberg News subsequently reported and the company acknowledged that it learned of suspicious activity in its computer system from its own personnel Nov. 12.

“We learned that after these criminals entered our network, a small amount of their activity was logged and surfaced to our team,” the company said after the Bloomberg story, and reiterated Tuesday. “That activity was evaluated and acted upon. Based on their interpretation and evaluation of that activity, the team determined that it did not warrant immediate follow-up. With the benefit of hindsight, we are investigating whether if different judgments had been made the outcome may have been different.”

Bloomberg reported Tuesday that Mulligan will testify to those facts in his committee appearance Wednesday. Target declined to comment.

Target faces dozens of lawsuits and tens of millions — perhaps even hundreds of millions — of dollars in expenses as it tries to explain and fix the holes in a cyber security system in which it invested hundreds of millions.

Hackers eventually got access to credit and debit card information and personal information for as many as 110 million customers.