Must-read report in today’s NYT:

The National Security Agency and its British counterpart issued an unusual warning in October: The Russians were back and growing stealthier.

Groups linked to Russia’s intelligence agencies, they noted, had recently been uncovered boring into the network of an elite Iranian hacking unit and attacking governments and private companies in the Middle East and Britain — hoping Tehran would be blamed for the havoc.

For federal and state officials charged with readying defenses for the 2020 election, it was a clear message that the next cyberwar was not going to be like the last. The landscape is evolving, and the piggybacking on Iranian networks was an example of what America’s election-security officials and experts face as the United States enters what is shaping up to be an ugly campaign season marred by hacking and disinformation.