Target Black Friday 2013:  Target admitted it failed to take immediate actions after its security software detected a possible security breach on Black Friday November 2013. 

According to Bloomberg Businessweek, Targert installed a $1.6 million malware detection tool from FireEye months before Black Friday 2013.  Just before Black Friday 2013, someone installed malware in Target's security and payments system designed to steal every credit card used at the company's 1,797 U.S. stores. FireEye Inc. sent security breach alerts, branded as "malware.binary," to Target's security team, but  the alerts were disregarded.

The Target Black Friday report, was based on a two-month investigation.Bloomberg Businessweek spoke to over 10 former Target employees who worked with Target's data security operation. They also spoke to eight people with specific knowledge of the Black Friday 2013 hack, including former employees, security researchers, and law enforcement officials. The findings contradict Target's statements about Black Friday. 

Shane Shook, an executive with Cylance Inc., told Reuters "They are bombarded with alerts. They get so many that they just don't respond to everything. It is completely understandable how this happened."

Target spokeswoman Molly Snyder told Reuters, "With the benefit of hindsight, we are investigating whether if different judgments had been made the outcome may have been different."

Target announced that the Black Friday data breach of 2013 could reach up to 100 million records, putting the Target Black Friday breach in the same category of massive hack attacks against Adobe and Sony. The Target Black Friday breach was caused by malware on store point-of-sale systems.

Consumer watchdogs urge customers who shopped at Target during the Black Friday time period to check their credit card statements. Custoners should change their PIN in the aftermath of the massive breach that happened at Target Stores on Black Friday.

Target originally announced that cybercriminals stole 40,000,000 payment card records. They said "As part of Target's ongoing forensic investigation, it has been determined that certain guest information - separate from the payment card data previously disclosed - was taken from Target. This theft is not a new breach, but was uncovered as part of the ongoing investigation. At this time, the investigation has determined that the stolen information includes names, mailing addresses, phone numbers or email addresses for up to 70 million individuals sucked up by cybercriminals."

Target promised that "Guests will have zero liability for the cost of any fraudulent charges arising from the breach. To provide further peace of mind, Target is offering one year of free credit monitoring and identity theft protection to all Target guests who shopped our U.S stores. Guests will have three months to enroll in the program. Additional details will be shared next week."

Target Black Friday stolen data included names, numbers, expiration dates and data taken from the magnetic strip when credit or debit cards are swiped.  The Target Black Friday hackers may be able to reproduce credit and debit cards and use them to withdraw cash from ATMs.

Target said some customers have been unable to use its gift cards because they weren't fully activated.

Target has been working to retain customers' loyalty. Target says its encryption system would not give the Black Friday hackers access to the encryption key. Target says only the external payment processor can access that kind of information.

At the time, a Target spokesperson said "While we previously shared that encrypted data was obtained, this morning through additional forensics work we were able to confirm that strongly encrypted PIN data was removed. We remain confident that PIN numbers are safe and secure. The PIN information was fully encrypted at the keypad, remained encrypted within our system, and remained encrypted when it was removed from our systems."