The disclosed computer-implemented method for estimating confidence scores of unverified signatures may include (1) detecting a potentially malicious event that triggers a malware signature whose confidence score is above a certain threshold, (2) detecting another event that triggers another signature whose confidence score is unknown, (3) determining that the potentially malicious event and the other event occurred within a certain time period of one another, and then (4) assigning, to the other signature, a confidence score based at least in part on the potentially malicious event and the other event occurring within the certain time period of one another. Various other methods, systems, and computer-readable media are also disclosed.