@misc{FealVallinaGambaetal., author = {Feal, {\´A}lvaro and Vallina, Pelayo and Gamba, Julien and Pastrana, Sergio and Nappa, Antonio and Hohlfeld, Oliver and Vallina-Rodriguez, Narseo and Tapiador, Juan}, title = {Blocklist Babel: On the Transparency and Dynamics of Open Source Blocklisting}, series = {IEEE Transactions on Network and Service Management}, journal = {IEEE Transactions on Network and Service Management}, publisher = {IEEE}, issn = {1932-4537}, doi = {10.1109/TNSM.2021.3075552}, pages = {16}, abstract = {Blocklists constitute a widely-used Internet security mechanism to filter undesired network traffic based on IP/domain reputation and behavior. Many blocklists are distributed in open source form by threat intelligence providers who aggregate and process input from their own sensors, but also from thirdparty feeds or providers. Despite their wide adoption, many open-source blocklist providers lack clear documentation about their structure, curation process, contents, dynamics, and interrelationships with other providers. In this paper, we perform a transparency and content analysis of 2,093 free and open source blocklists with the aim of exploring those questions. To that end, we perform a longitudinal 6-month crawling campaign yielding more than 13.5M unique records. This allows us to shed light on their nature, dynamics, inter-provider relationships, and transparency. Specifically, we discuss how the lack of consensus on distribution formats, blocklist labeling taxonomy, content focus, and temporal dynamics creates a complex ecosystem that complicates their combined crawling, aggregation and use. We also provide observations regarding their generally low overlap as well as acute differences in terms of liveness (i.e., how frequently records get indexed and removed from the list) and the lack of documentation about their data collection processes, nature and intended purpose. We conclude the paper with recommendations in terms of transparency, accountability, and standardization.}, language = {en} } @misc{MorenoPastranaReelfsetal., author = {Moreno, Jos{\´e} Miguel and Pastrana, Sergio and Reelfs, Jens Helge and Vallina, Pelayo and Panchenko, Andriy and Smaragdakis, Georgios and Hohlfeld, Oliver and Vallina-Rodriguez, Narseo and Tapiador, Juan}, title = {Reviewing War: Unconventional User Reviews as a Side Channel to Circumvent Information Controls}, doi = {10.48550/arXiv.2302.00598}, pages = {11}, abstract = {During the first days of the 2022 Russian invasion of Ukraine, Russia's media regulator blocked access to many global social media platforms and news sites, including Twitter, Facebook, and the BBC. To bypass the information controls set by Russian authorities, pro-Ukrainian groups explored unconventional ways to reach out to the Russian population, such as posting war-related content in the user reviews of Russian business available on Google Maps or Tripadvisor. This paper provides a first analysis of this new phenomenon by analyzing the creative strategies to avoid state censorship. Specifically, we analyze reviews posted on these platforms from the beginning of the conflict to September 2022. We measure the channeling of war messages through user reviews in Tripadvisor and Google Maps, as well as in VK, a popular Russian social network. Our analysis of the content posted on these services reveals that users leveraged these platforms to seek and exchange humanitarian and travel advice, but also to disseminate disinformation and polarized messages. Finally, we analyze the response of platforms in terms of content moderation and their impact.}, language = {en} }