"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." Psaki's warnings followed a tweet by national security adviser Jake Sullivan Thursday evening that underscored how concerned the Biden administration is. He urged IT administrators nationwide to install software fixes immediately. Sullivan said the US government is monitoring reports that US think tanks may have been compromised by the attack, as well as "defense industrial base entities." 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.
The cybersecurity firm FireEye said Thursday it had already identified a number of specific victims, including "US-based retailers, local governments, a university, and an engineering firm." 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." Microsoft disclosed this week that it had become aware of several vulnerabilities in its server software being exploited by suspected Chinese hackers. In the past, Microsoft said, the hacker group responsible -- which Microsoft is calling Hafnium -- has gone after "infectious disease researchers, law firms, higher education institutions, defense contractors, policy think tanks, and NGOs." The group in question had not been previously identified to the public, according to Microsoft. The announcement marked the latest information security crisis to hit the US after FireEye, Microsoft and others reported a suspected Russian hacking campaign that began by infiltrating the IT software company SolarWinds. That effort has led to the compromise of at least nine federal agencies and dozens of private businesses. 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.