The American failure to respond to a Russian plan to pay the Taliban to kill US troops raises profound questions.
Intelligence officials had long suspected that Russian operatives were behind the German cyberattack,but it took five years to collect the evidence.
US President Donald Trump has repeatedly said,without evidence,that the Obama administration acted corruptly.
Lindsey Graham,chairman of the Senate Judiciary Committee,announced he will lead in-depth hearings next month into the FBI's probe of Russian interference in the 2016 election.
The Justice Department's bombshell May 7 decision to drop its case against Flynn came on the heels of growing pressure from Trump and Trump's political allies.
The case against Michael Flynn had become a political cause for Trump and his supporters and Trump had signalled a pardon. But the AG short-circuited it.
For the past three years prosecutors maintained that Flynn lied to the FBI in a January 2017 interview about his dealings with the Russian ambassador.
The records reveal the extent of communications between the two. Assange's Wikileaks published Democratic emails hacked by Russians during the 2016 US presidential election.
Trump,who has bristled at suggestions that foreign interference helped his upset 2016 victory,has sought to discredit the intelligence agencies'findings.
The scolding was unusually blunt,with the judge saying the Attorney-General had appeared to make a"calculated attempt"to influence public opinion about the report in ways favourable to Trump.
Hunter Biden's role has been attacked as corrupt without evidence by Trump and other Republicans in Congress.