Ad-tech enables publishers to programmatically sell their ad inventory to millions of demand partners through a complex supply chain. Bogus or low quality publishers can exploit the opaque nature of the ad-tech to deceptively monetize their ad inventory. In this paper, we investigate for the first time how misinformation sites subvert the ad-tech transparency standards and pool their ad inventory with unrelated sites to circumvent brand safety protections. We find that a few major ad exchanges are disproportionately responsible for the dark pools that are exploited by misinformation websites. We further find evidence that dark pooling allows misinformation sites to deceptively sell their ad inventory to reputable brands. We conclude with a discussion of potential countermeasures such as better vetting of ad exchange partners, adoption of new ad-tech transparency standards that enable end-to-end validation of the ad-tech supply chain, as well as widespread deployment of independent audits like ours.

翻译：广告技术使发布商能够通过复杂的供应链，以程序化方式将其广告库存销售给数百万个需求方合作伙伴。虚假或低质量发布商可利用广告技术的不透明性，欺骗性地将其广告库存货币化。在本文中，我们首次研究了虚假信息网站如何颠覆广告技术透明度标准，并将其广告库存与无关网站进行池化以规避品牌安全保护。我们发现，少数几家主要广告交易平台对虚假信息网站利用的暗池不成比例地负有责任。我们进一步发现证据表明，暗池化使虚假信息网站能够欺骗性地将其广告库存销售给知名品牌。最后，我们讨论了潜在对策，例如加强对广告交易平台合作伙伴的审核、采用支持广告技术供应链端到端验证的新透明度标准，以及广泛部署像我们这样的独立审计。