Tag of the Dead: How Terminated SaaS Tags Become Zombies

Abstract

—Software as a Service (SaaS) dies. Several SaaS die every day because it becomes too difficult to continue their business. SaaS lets website owners install a small amount of code, called a tag, on a website to extend its functionality of the website. However, sometimes that tag becomes a zombie. In this paper, we coordinate two studies to reveal the danger of the zombification of tags. (1) A research of domains used by dead SaaS tags. (2) An investigation of websites with dead tags. The results of our work show that of the 53 domains used with 49 dead SaaS tags, 18 domains have already been re-registered by a third party or are ready to be re-registered. We also scanned about 1.15 million websites of domestic companies and found 26 dead SaaS tags on approximately 18,000 websites. Finally, we found that three new SaaS tags have been abused by attackers, indicating the danger of zombification tags.