https://www.lawfareblog.com/scope-muelle...-uncovered
"What is Mueller’s Jurisdiction?
The order by Deputy Attorney General Rod Rosenstein appointing Mueller states:
(b) The Special Counsel is authorized to conduct the investigation confirmed by then-FBI Director James B. Comey in testimony before the House Permanent Select Committee on Intelligence on March 20, 2017, including:
(i) any links and/or coordination between the Russian government and individuals associated with the campaign of President Donald Trump; and
(ii) any matters that arose or may arise directly from the investigation; and
(iii) any other matters within the scope of 28 C.F.R. § 600.4(a).
© If the Special Counsel believes it is necessary and appropriate, the Special Counsel is authorized to prosecute federal crimes arising from the investigation of these matters. . . . .
Comey’s March testimony that Rosenstein incorporated by reference was as follows:
I have been authorized by the Department of Justice to confirm that the FBI, as part of our counterintelligence mission, is investigating the Russian government's efforts to interfere in the 2016 presidential election and that includes investigating the nature of any links between individuals associated with the Trump campaign and the Russian government and whether there was any coordination between the campaign and Russia's efforts. As with any counterintelligence investigation, this will also include an assessment of whether any crimes were committed.
In March, Comey did not publicly reveal details of what exactly the FBI is investigating. But news reports based on leaks, coming in February before Comey spoke, provided a fuller picture, at least as of then:
The FBI's Pittsburgh field office, which runs many cyber security investigations, is trying to identify the people behind breaches of the Democratic National Committee's computer systems . . . . Meanwhile the bureau’s San Francisco office is trying to identify the people who called themselves “Guccifer 2” and posted emails stolen from Clinton campaign manager John Podesta’s account . . . . Beyond the two FBI field offices, FBI counterintelligence agents based in Washington are pursuing leads from informants and foreign communications intercepts, two of the people said. This counterintelligence inquiry includes but is not limited to examination of financial transactions by Russian individuals and companies who are believed to have links to Trump associates."