Analysis of Competing Hypotheses (ACH) is an analytic process designed to help an analyst or a team of analysts evaluate multiple competing hypotheses on an issue fairly and objectively. ACH assists in identifying and analyzing the evidence for and against each hypothesis, ultimately aiding in determining the most likely explanation. In the scenario where a team of threat intelligence analysts has various theories on a particular malware, ACH would be the most appropriate method to assess these competing theories systematically. ACH involves listing all possible hypotheses, collecting data and evidence, and assessing the evidence's consistency with each hypothesis. This process helps in minimizing cognitive biases and making a more informed decision on the most consistent theory. Reference:

Richards J. Heuer Jr., 'Psychology of Intelligence Analysis,' Central Intelligence Agency

'A Tradecraft Primer: Structured Analytic Techniques for Improving Intelligence Analysis,' Central Intelligence Agency