partner: UNITN; project: NESSoS; no tier; citation: 0

Cybercrime is notoriously maintained and empowered by the underground economy, manifested in black markets. In such markets, attack tools and vulnerability exploits are constantly traded. In this paper, we focus on making a quantitative assessment of the risk of attacks coming from such markets, and investigating the expected reduction in overall attacks against final users if, for example, vulnerabilities traded in the black markets were all to be promptly patched. In order to conduct the analysis, we mainly use the data on (a) vulnerabilities bundled in 90+ attack tools traded in the black markets collected by us; (b) actual records of $9times 10^7$ attacks collected from %thanks to our participation with Symantec's Data Sharing Programme WINE. Our results illustrate that black market vulnerabilities are an important source of risk for the population of users; we further show that vulnerability mitigation strategies based on black markets monitoring may outperform traditional strategies based on vulnerability CVSS scores by providing up to 20% more expected reduction in attacks.