Control: 10.1.1 Ensure soft delete for Azure File Shares is Enabled

Description

Azure Files offers soft delete for file shares, allowing you to easily recover your data when it is mistakenly deleted by an application or another storage account user.

Important data could be accidentally deleted or removed by a malicious actor. With soft delete enabled, the data is retained for the defined retention period before permanent deletion, allowing for recovery of the data.

Remediation

From Azure Portal

Go to Storage Accounts.
For each storage account with file shares, under Data storage, click File shares.
Under File share settings, click the value next to Soft delete.
Under Soft delete for all file shares, click the toggle to set it to Enabled.
Under Retention policies, set an appropriate number of days to retain soft deleted data between 1 and 365, inclusive.
Click Save.

From Azure CLI

For each storage account requiring remediation, run the following command to enable soft delete for file shares and set an appropriate number of days for deleted data to be retained, between 1 and 365, inclusive:

az storage account file-service-properties update --account-name <storage-account> --enable-delete-retention true --delete-retention-days <retention-days>

From PowerShell

Update-AzStorageFileServiceProperty -ResourceGroupName <resource-group> -AccountName <storage-account> -EnableShareDeleteRetentionPolicy $true -ShareRetentionDays <retention-days>

Default Value

Soft delete is enabled by default at the storage account file share setting level.

Usage

Run the control in your terminal:

powerpipe control run azure_compliance.control.cis_v400_10_1_1

Snapshot and share results via Turbot Pipes:

powerpipe login
powerpipe control run azure_compliance.control.cis_v400_10_1_1 --share

SQL

This control uses a named query:

select
  sa.id as resource,
  case
    when file_soft_delete_enabled and file_soft_delete_retention_days between 1 and 365 then 'ok'
    else 'alarm'
  end as status,
  case
    when not file_soft_delete_enabled then name || ' file share soft delete disabled.'
    when file_soft_delete_retention_days < 1 or file_soft_delete_retention_days > 365 
      then name || ' file share soft delete retention days (' || file_soft_delete_retention_days || ') not between 1 and 365.'
    else name || ' file share soft delete enabled with ' || file_soft_delete_retention_days || ' days retention.'
  end as reason
  
  , sa.resource_group as resource_group
  , sub.display_name as subscription
from
  azure_storage_account sa,
  azure_subscription sub
where
  sub.subscription_id = sa.subscription_id;