Techniques for malware domain detection using passive Domain Name Service (DNS) are disclosed. In some embodiments, malware domain detection using passive DNS includes generating a malware association graph that associates a plurality of malware samples with malware source information, in which the malware source information includes a first domain; generating a reputation score for the first domain using the malware association graph and passive DNS information; and determining whether the first domain is a malware domain based on the reputation score for the first domain.