According to the DHS agent portrayed in this video, the Secret Service has responded to network intrusions at businesses throughout the United States that have been impacted by through their point-of-sale systems.
A. unauthorized wireless traffic
B. spoofers
C. malware
D. spam
E. data recovery failures

C. malware

Explanation:

The Secret Service Agent carefully analyzed and suspected that intruders were infected into the Internet network system with malicious malware that could affect the entire network system at point-of-sale systems in the United States. Malware is a virus that is used by hackers and cyber criminals to steal data and information or to mislead the public or government.

so correct option is  C. malware