A recent report citing sources familiar with the investigation said hackers were able to gain access to Target's customer data from an HVAC subcontractor, wrote VentureBeat.

Cybersecurity journalist Brian Krebs wrote a report on his blog about the Target data breach. Krebs' sources said network log-on credentials have been linked to a heating, refrigeration, and air conditioning provider in Pennsylvania. The hacking attack on Target compromised data from 40 million payment cards over the holidays and personal data of around 70 million customers. Krebs originally publicized the Target data breach, the report detailed.

This latest report further confirms that the data hack was conducted by an organized and professional group of hackers. According to Krebs, the attackers took advantage of a two-week window around Thanksgiving to transfer their malware to several cash registers in the retail store for beta testing. They also used infected computers in the US and Brazil for temporary storage of their stolen data. The goons are reportedly in Russia and Eastern Europe, the report explained.

The CFO of Target said the retail chain is investing in chip-based credit cards. This technology is more secure than the commonly-used magnetic striped ones, VentureBeat reported.