Octo Tempest, a financially motivated cybercrime group, employs social engineering and identity compromise to infiltrate systems and deploy ransomware. Their tactics involve exploiting weaknesses in identity systems to steal data, making them a versatile threat due to their use of native English speakers and rapid adaptability. Businesses need to be vigilant, employing response playbooks focused on forensics and managing identity and access systems to combat these threats.
Organizations should implement several key measures to secure their environments against Octo Tempest. This includes regaining administrative control of Microsoft Entra ID by using break-glass accounts for emergency access, switching federation authentication to Managed mode, and auditing service principals to eliminate unnecessary permissions. Conditional Access policies requiring multi-factor authentication (MFA) and blocking legacy authentication protocols are crucial steps in safeguarding resources.
In response to an Octo Tempest intrusion, organizations should take immediate action to mitigate damage. This involves reviewing and adjusting Network Security Groups, Azure Firewall rules, and access control for Azure Management Groups. Implementing Multi-Administrator Approval (MAA) in Intune and investigating all MFA registrations during the incident can help secure accounts and prevent further exploitation.
For severe compromises, additional actions are necessary, such as isolating and sanitizing domain controllers, rebuilding the Active Directory forest if needed, and rotating compromised credentials. Adopting the AD Tiering model can also help mitigate Pass-the-Hash attacks by creating segregated privileged accounts and ensuring control plane isolation.
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