In October 2016, media outlets reported that data collected by some of the world’s most renowned cybersecurity experts had identified frequent and unexplained communications between an email server used by the Trump Organization and Alfa Bank, one of Russia’s largest financial institutions. Those publications set off speculation about a possible secret back-channel of communications, as well as a series of lawsuits and investigations that culminated last week with the indictment of the same former federal cybercrime prosecutor who brought the data to the attention of the FBI five years ago.

The first page of Alfa Bank’s 2020 complaint.

Since 2018, access to an exhaustive report commissioned by the U.S. Senate Armed Services Committee on data that prompted those experts to seek out the FBI has been limited to a handful of Senate committee leaders, Alfa Bank, and special prosecutors appointed to look into the origins of the FBI investigation on alleged ties between Trump and Russia.

That report is now public, ironically thanks to a pair of lawsuits filed by Alfa Bank, which doesn’t directly dispute the information collected by the researchers. Rather, it claims that the data they found was the result of a “highly sophisticated cyberattacks against it in 2016 and 2017” intended “to fabricate apparent communications” between Alfa Bank and the Trump Organization.

The data at issue refers to communications traversing the Domain Name System (DNS), a global database that maps computer-friendly coordinates like Internet addresses (e.g., 8.8.8.8) to more human-friendly domain names (example.com). Whenever an Internet user gets online to visit a website or send an email, the user’s device sends a query through the Domain Name System.

Many different entities capture and record this DNS data as it traverses the public Internet, allowing researchers to go back later and see which Internet addresses resolved to what domain names, when, and for how long. Sometimes the metadata generated by these lookups can be used to identify or infer persistent network connections between different Internet hosts.

The DNS strangeness was first identified in 2016 by a group of…