Understanding and Remediating Compromised User Accounts in Entra

2025-02-13

In the realm of cybersecurity, identifying a compromised user account is only the first step. The action of confirming a user as compromised in Entra (formerly Azure AD) merely sets the `RiskLevel` to high and updates the `RiskState` of the Entra object. However, this action alone does not remediate the risk. To effectively mitigate the threat, additional steps must be taken.

Key Steps to Remediate Compromised Accounts:

1. Conditional Access (CA) Policies: If your organization is licensed for Conditional Access, ensure that you have policies in place to block or remediate compromised accounts. These policies can enforce multi-factor authentication (MFA), require password changes, or even block access entirely until the account is secured.

2. Incident Response Playbook: Develop and maintain a playbook specifically for handling compromised accounts. This playbook should outline the steps to take when an account is confirmed as compromised, including communication protocols, remediation steps, and post-incident review.

Example Commands and Scripts:

1. Check User Risk Level in Entra (Azure AD):

   </li>
   </ol>
   
   <h1>Connect to Azure AD</h1>
   
   <p>Connect-AzureAD
   
   <h1>Get user risk details</h1>
   
   Get-AzureADUserRisk -ObjectId <UserObjectId>
   

   2. Force Password Reset for Compromised User:

   
   <h1>Force password reset for a compromised user</h1>
   
   Set-AzureADUserPassword -ObjectId <UserObjectId> -ForceChangePassword $true
   

   3. Block User Account:

   
   <h1>Block a compromised user account</h1>
   
   Set-AzureADUser -ObjectId <UserObjectId> -AccountEnabled $false
   

   4. Enable Conditional Access Policy:

   
   <h1>Example of enabling a Conditional Access policy</h1>
   
   <h1>Note: This is a simplified example. Actual policies should be configured via the Azure portal.</h1>
   
   New-AzureADMSConditionalAccessPolicy -DisplayName "Block Compromised Users" -State "enabled" -Conditions <ConditionsObject> -GrantControls <GrantControlsObject>
   

   What Undercode Say:

   In the ever-evolving landscape of cybersecurity, the importance of not just detecting but also effectively remediating compromised accounts cannot be overstated. The process of confirming a user as compromised in Entra is a critical first step, but it is merely the beginning of a comprehensive response strategy.

   To truly secure your environment, you must leverage Conditional Access policies, which can automatically enforce security measures such as MFA or password resets. Additionally, having a well-defined incident response playbook ensures that your team can act swiftly and effectively when a compromise is detected.

   Beyond Entra, Linux-based systems offer a plethora of tools and commands that can aid in securing user accounts and systems. For instance, using `fail2ban` to block brute force attacks, or `chage` to enforce password aging policies, can significantly enhance your security posture.

   
   <h1>Install fail2ban on a Linux system</h1>
   
   sudo apt-get install fail2ban
   
   <h1>Configure fail2ban to monitor SSH login attempts</h1>
   
   sudo nano /etc/fail2ban/jail.local
   
   <h1>Add the following lines to the file</h1>
   
   [sshd]
   enabled = true
   filter = sshd
   action = iptables[name=SSH, port=ssh, protocol=tcp]
   logpath = /var/log/auth.log
   maxretry = 3
   bantime = 3600
   
   <h1>Restart fail2ban to apply changes</h1>
   
   sudo systemctl restart fail2ban
   

   
   <h1>Enforce password aging policies using chage</h1>
   
   sudo chage -M 90 -m 7 -W 14 <username>
   

   In conclusion, while Entra provides essential tools for identifying compromised accounts, the real work begins after detection. By implementing robust Conditional Access policies, maintaining a detailed incident response playbook, and leveraging Linux-based security tools, you can significantly reduce the risk posed by compromised accounts. Always remember, cybersecurity is a continuous process, and staying vigilant is key to protecting your digital assets.

   For further reading on Entra and Conditional Access policies, visit the official Microsoft documentation:
   – Entra Documentation
   – Conditional Access Policies

   References:

   Hackers Feeds, Undercode AI