A recent advisory issued by the UK National Cyber Security Centre (NCSC) and international partners shed light on the tactics, techniques, and procedures (TTPs) of the cyber espionage group APT29, also known as Midnight Blizzard or Cozy Bear. This group, believed to be part of the Russian intelligence service SVR, has been observed adapting to the shifting landscape of government and corporate cloud infrastructure.

The advisory outlines APT29's strategies to gain initial access into cloud environments, emphasizing the need for enhanced detection and mitigation measures to counter their activities. The SVR actors have been expanding their targets beyond traditional sectors like governmental and healthcare to include aviation, education, law enforcement, and military organizations.

One key aspect of APT29's operations is the targeting of service accounts, which are often highly privileged and lack multi-factor authentication (MFA) protection, making them vulnerable to compromise. Additionally, the group has been observed exploiting dormant accounts and utilizing system-issued access tokens to bypass authentication measures.

The advisory also highlights APT29's techniques such as password spraying, credential reuse, and "MFA bombing" to bypass security controls and gain unauthorized access to cloud environments. The actors have shown sophistication in evading detection, using tactics like residential proxies to hide their malicious activities and blend in with legitimate traffic.

While the SVR's capabilities include sophisticated attacks like the 2020 SolarWinds supply chain compromise, organizations are encouraged to implement strong cybersecurity fundamentals to defend against such threats. Mitigations recommended in the advisory, in alignment with the MITRE ATT&CK® framework, aim to bolster defenses against APT29's initial access vectors and thwart their post-compromise activities.

For network defenders operating in cloud environments, guidance from entities like NCSC, CISA, and Microsoft on protecting assets stored in the cloud is essential. By staying abreast of evolving TTPs and fortifying security measures, organizations can better safeguard their networks against the persistent threat posed by APT29 and other sophisticated threat actors.