“This is an active threat,” White House press secretary Jen Psaki said Friday. “Everyone running these servers — government, private sector, academia — needs to act now to patch them.”
Later on Friday, the Cybersecurity and Infrastructure Security Agency underscored the risk in unusually plain language, stating in a tweet that the malicious activity, if left unchecked, could “enable an attacker to gain control of an entire enterprise network.”
In a rare step, White House officials have urged private sector organizations running localized installations of Microsoft Exchange server software to install several critical updates that were released in what information security experts described as an emergency patch release.
Pentagon press secretary John Kirby told reporters Friday the Defense Department is currently working to determine if it has been negatively affected by the vulnerability.
“We’re aware of it, and we’re assessing it,” Kirby said. “And that’s really as far as I’m able to go right now.”
But the malicious activity disclosed this week is not in any way related to the SolarWinds hack, Microsoft said Tuesday.
Microsoft typically releases software updates on the second Tuesday of each month. But in a sign of the seriousness of the threat, Microsoft published the patches addressing the new vulnerabilities — which had never been detected until now — a week early.
‘We urge network operators to take it very seriously’
“We urge network operators to take it very seriously,” Psaki said of the directive. The administration is concerned there as a “large number of victims,” she added.
One person working at a Washington think tank told CNN both her work and personal e-mail accounts were hit by the attackers. Microsoft sent her a warning that a foreign government was behind it. AOL sent a similar notification for the personal account.
The person was then visited by FBI agents who showed up on her doorstep, repeating that this was indeed an ongoing, sophisticated hack by a foreign government and that there is a nationwide FBI investigation underway.
The attackers had used their unauthorized access to e-mail the person’s contacts, “tailoring [the messages] in a way that the recipient will not doubt I am the sender.” The attackers’ fraudulent emails sent in the person’s name included invitations to non-existent conferences and referred to an article in her name and a book in a colleague’s name, neither of which was written by them.
Each message, the person said, came with links asking people to click on them.
The US government’s unusually public response to the incident was a surprise to many experts, a reflection of both the Biden administration’s focus on cyber issues compared to the Trump White House as well as the scale of the threat.
“When you wake up to the [National Security Advisor] and [Press Secretary] tweeting about cyber,” National Security Agency communications official Bailey Bickley tweeted from her personal account, appending a “starstruck” emoji and quoting Sullivan’s tweet from the night before.
CLARIFICATION: This story has been updated to reflect NSA official Bailey Bickley was tweeting on her personal account and not speaking for the NSA.
CNN’s Michael Conte and Oren Liebermann contributed to this report.