With Microsoft acknowledging for the first time this past week that suspected Russian hackers behind a massive government security breach also gained access to its source code, pressure is mounting on US officials and cybersecurity experts to explain how the attackers infiltrated various US computer networks, what they did once inside and the steps that are being taken to mitigate the damage.

As US officials struggle with the fallout, questions are swirling about whether the agency tasked with protecting the nation from cyberattacks is up to the job.

On Wednesday, the Cybersecurity and Infrastructure Security Agency, (CISA) signaled it’s still working to patch the known vulnerabilities, advising agencies to update their software from SolarWinds, a private contractor attackers exploited to gain access into potentially thousands of public and private sector organizations.

Congressional Democrats and the Biden transition team are demanding more information about the massive hacking campaign, calling on the Trump administration to address concerns about its handling of the fallout and perceived lack of transparency in the weeks since the data breach was first discovered.

The Biden team in particular has stated that it’s been stonewalled by Trump officials in its effort to learn more about key national security issues, including the hack.

Trump administration officials say those accusations are exaggerated but have also acknowledged they are wary of any transition activity that could provide the Biden team a head start in dismantling the President’s priorities.

To date, the White House has offered few public details about what is believed to be the most significant cyber operation targeting the US in years. The lack of…