Threat assessment of systems is critical to organizations' security policy. Identifying systems likely to be at-risk by threat actors can help organizations better defend against likely cyber attacks. Currently, identifying such systems to a large extent is guided by the Common Vulnerability Scoring System (CVSS). Previous research has demonstrated poor correlation between a high CVSS score and at-risk systems. In this paper, we look at hacker discussions on darkweb marketplaces and forums to identify the platforms, vendors, and products likely to be at-risk by hackers. We propose a reasoning system that combines DeLP (Defeasible Logic Programming) and machine learning classifiers to identify systems based on hacker discussions observed on the darkweb. The resulting system is therefore a hybrid between classical knowledge representation and reasoning techniques and machine learning classifiers. We evaluate the system on hacker discussions collected from nearly 300 darkweb forums and marketplaces provided by a threat intelligence company. We improved precision by 15%-57% while maintaining recall over baseline approaches.