1. A method to localize anomalies in a communication network, the method comprising: identifying, with a processor, a first set of abnormal nodes in the communication network; including, with the processor, respective ones of the first set of the abnormal nodes having a number of normal direct descendent nodes that is less than a combined number of abnormal direct descendent nodes and indeterminate direct descendent nodes in a set of candidate nodes; and iteratively selecting, with operations performed by the processor, ones of the set of the candidate nodes to include in a set of root cause abnormal nodes representing sources of the anomalies in the communication network, the operations including: selecting a first one of the set of the candidate nodes that covers a largest subset of the abnormal nodes from the first set of the abnormal nodes to include in the set of the root cause abnormal nodes; removing the largest subset of the abnormal nodes from the first set of the abnormal nodes to determine an updated first set of the abnormal nodes; and selecting a second one of the set of the candidate nodes that covers an updated largest subset of the abnormal nodes from the updated first set of the abnormal nodes to include in the set of the root cause abnormal nodes.