In the context of Cisco Advanced Malware Protection (AMP), when a file is submitted to the Threat Grid analysis engine, it undergoes a thorough behavioral analysis to determine if it exhibits characteristics typical of malware. The Threat Grid provides detailed reports that include behavioral indicators of compromise (IoCs), which are actions or artifacts on a network or an endpoint that with high confidence indicate a breach.
In this case, the report generated by the Threat Grid for a low prevalence file shows high severity scores for the behavioral indicators. This suggests that the behaviors observed are strongly indicative of malicious activity, specifically ransomware. The high scores reflect the Threat Grid's confidence in the malicious nature of the file based on its observed behaviors, which may include patterns of encryption consistent with ransomware, network activity that matches known ransomware command and control patterns, or file system changes that are characteristic of ransomware encryption.
Therefore, the correct answer is C, as the high scores on the behavioral indicators strongly suggest the presence of ransomware, justifying the execution of the ransomware detection mechanisms by Cisco AMP.