The Federal Bureau of Investigation (FBI) and Cybersecurity and Infrastructure Security Agency (CISA) are releasing this joint Cybersecurity Advisory (CSA) to warn organizations that Russian state-sponsored cyber actors have gained network access through exploitation of default MFA protocols and a known vulnerability. As early as May 2021, Russian state-sponsored cyber actors took advantage of a misconfigured account set to default MFA protocols at a non-governmental organization (NGO), allowing them to enroll a new device for MFA and access the victim network.
The actors then exploited a critical Windows Print Spooler vulnerability, “PrintNightmare” (CVE-2021-34527) to run arbitrary code with system privileges. Russian state-sponsored cyber actors successfully exploited the vulnerability while targeting an NGO using Cisco’s Duo MFA, enabling access to cloud and email accounts for document exfiltration.
Source: U.S. Federal Bureau of Investigation Cyber Division