It’s all hearsay and personal opinion.
But the Justice Department said in a letter to Congress in June that the Durham review was "broad in scope and multifaceted, and is intended to illuminate open questions regarding the activities of U.S. and foreign intelligence services as well as non-governmental organizations and individuals."
But the escalation of Durham's inquiry into a criminal case is politically important to Republicans, who call the Russia investigation the work of "biased" conspirators within a "deep state" who abused their powers out of political animus toward Trump and his campaign.
https://www.npr.org/2019/10/25/773358670/doj-review-of-russia-probe-now-is-criminal-case-dems-charge-wh-interference