A Target Corp. team of security experts, armed with a malware detection tool made by FireEye Inc., alerted company officials about a possible data breach on Nov. 30, but they failed to respond to the warning signs, according to a media report on Thursday.

The security specialists in Bangalore, India, monitoring computer logs found FireEye's alerts from Nov. 30 and notified Target officials in Minneapolis, Bloomberg Businessweek reported. They also found more alerts from Dec. 2, when more malware surfaced.

Such warnings, if heeded, could have cut short the massive data breach that affected millions of customers who shopped at the nation's No. 3 retailer between Nov. 27 and Dec. 18 — the height of the U.S. holiday shopping season.

Some 40 million credit and debit card records were stolen from the retailer, along with 70 million other records with customer information such as addresses and telephone numbers.

Congress is investigating the breach along with lapses that surfaced at other retailers, and credit card companies are pushing for better security.

Shares of Target took a hit after news of the security lapse surfaces in mid-December but recovered after the company offered assurances last month. Its shares were largely unchanged in pre-market trading on the New York Stock Exchange on Thursday.

Shares of FireEye were up 2 percent on Nasdaq.

Bloomberg, citing a source who has consulted on the Target's investigation, said hackers deployed a custom-made code on Nov. 30 that triggered a FireEye alert for the malware, including details on the servers where stolen data was to be delivered.

The security system's automatic function to delete such malware was turned off by Target's security team, the report said, citing two people who audited FireEye's role after the breach.

Target Chief Executive Gregg Steinhafel, in a statement to Bloomberg, said the retailer was still reviewing its "people, processes and technology" in the wake of the breach.

"As the investigation is not complete, we don't believe it's constructive to engage in speculation without the benefit of the final analysis," Steinhafel wrote, according to the report.

He said the company had "already taken significant steps." Target earlier this month said it was overhauling its information security practices.

Representatives for Target and FireEye could not immediately be reached to comment on the report.