Your file shares are getting hit. Not “might get hit someday”—they’re already in the crosshairs. Ransomware attacks continue climbing, with incidents rising more than 30% year-over-year. That’s not a trend. That’s a stampede, and your Azure NetApp Files volumes are standing in the path.
Here’s what makes this worse: attackers aren’t bothering with elaborate social engineering anymore. They’re going straight for cloud storage accounts like SharePoint, OneDrive, and—you guessed it—file shares sitting in Azure. One misconfigured NFS export, one overlooked SMB permission, and suddenly you’re explaining to your CEO why the quarterly reports are encrypted.
You need storage-level defense that catches attacks before they destroy your data. Advanced ransomware protection in Azure NetApp Files gives you machine learning detection that monitors encryption activity in real-time. Here’s how it works and what you need to know before implementing it.
What Advanced Ransomware Protection Actually Does
Advanced ransomware protection monitors three behavioral signals that indicate ransomware activity: file extension patterns, data entropy changes, and I/O volume spikes. The system learns what your volumes look like during normal operations—what file types you write, your typical I/O cadence, your data entropy distribution. When it detects deviations from that baseline, it creates a snapshot and flags the activity.
This approach catches both known ransomware variants and novel attacks because it’s not matching signatures—it’s detecting behavioral anomalies that indicate encryption activity, regardless of which ransomware family is doing the encrypting.
| Detection Signal | What It Monitors | Why This Catches Attacks |
|---|---|---|
| File extension types | Changes in file naming patterns | Ransomware appends extensions like .locked or .encrypted |
| Data entropy patterns | Randomness in file content | Encryption creates high entropy—encrypted files look statistically random |
| I/O patterns | Volume activity spikes | Mass file rewrites happen during ransomware encryption |
The machine learning model refines its understanding over time. As you mark alerts as false positives or confirmed threats, it gets smarter about what constitutes normal activity for your specific workload. A massive file rewrite might be ransomware in one environment and Tuesday’s batch processing job in another.
Key Insight: Backups are for disasters. Snapshots are for interruptions. You need both, but the snapshot is what saves you from paying the ransom.
How to Enable Ransomware Protection
You can’t enable advanced ransomware protection on existing volumes—it only works on newly created volumes. This means you’ll need to plan your migration strategy if you want to protect volumes already in production.
Step 1: Register the Feature
First, register the ransomware protection feature in your Azure subscription:
az feature register --namespace Microsoft.NetApp --name ANFAntiRansomware
Registration can take up to 60 minutes. Check status with:
az feature show --namespace Microsoft.NetApp --name ANFAntiRansomware --query "properties.state" -o tsv
Once the feature shows Registered, refresh the NetApp resource provider:
az provider register --namespace Microsoft.NetApp
Step 2: Enable Protection via Azure Portal
Here’s where the CLI falls short: Azure CLI doesn’t support the parameter to enable ransomware protection when creating volumes. You’ll need to use the Azure portal.
Navigate to your NetApp account in the portal, then:
-
Select Volumes → + Add volume
-
Configure your volume settings (name, quota, protocol type, network)
-
Go to the Data Protection tab
-
Check the box for Enable Advanced Ransomware Protection
-
Click Review + Create → Create
The portal is the only way to enable this feature during volume creation. Once protection is enabled, you can manage everything else—monitoring, verification, recovery—through the CLI.
Step 3: Verify Protection via CLI
After creating the volume in the portal, verify that protection is enabled:
az netappfiles volume show \
--resource-group $RESOURCE_GROUP \
--account-name $NETAPP_ACCOUNT \
--pool-name $CAPACITY_POOL \
--name $VOLUME_NAME \
--query "dataProtection" -o json
You should see ransomware protection listed in the data protection configuration.
Pro Tip: This limitation only applies to enabling protection. Once it’s active, you can monitor threats, list snapshots, and revert volumes entirely from the CLI—no portal required.
How to Monitor for Threats
Advanced ransomware protection creates activity log events when threats are detected. You can query these alerts through the Azure CLI to see what the system has flagged.
List recent activity log entries for a specific volume:
# Linux/WSL
az monitor activity-log list \
--resource-group $RESOURCE_GROUP \
--start-time $(date -u -d '24 hours ago' '+%Y-%m-%dT%H:%M:%SZ') \
--query "[?contains(resourceId, '$VOLUME_NAME')].{Time:eventTimestamp, Level:level, Status:status.value, Operation:operationName.localizedValue}" \
-o table
# macOS
az monitor activity-log list \
--resource-group $RESOURCE_GROUP \
--start-time $(date -u -v-24H '+%Y-%m-%dT%H:%M:%SZ') \
--query "[?contains(resourceId, '$VOLUME_NAME')].{Time:eventTimestamp, Level:level, Status:status.value, Operation:operationName.localizedValue}" \
-o table
Filter specifically for ransomware threat notifications:
# Linux/WSL
az monitor activity-log list \
--resource-group $RESOURCE_GROUP \
--start-time $(date -u -d '24 hours ago' '+%Y-%m-%dT%H:%M:%SZ') \
--query "[?contains(operationName.value, 'ransomware')].{Time:eventTimestamp, Status:status.value, Operation:operationName.localizedValue, Message:properties.message}" \
-o table
# macOS
az monitor activity-log list \
--resource-group $RESOURCE_GROUP \
--start-time $(date -u -v-24H '+%Y-%m-%dT%H:%M:%SZ') \
--query "[?contains(operationName.value, 'ransomware')].{Time:eventTimestamp, Status:status.value, Operation:operationName.localizedValue, Message:properties.message}" \
-o table
When the system detects suspicious activity, it automatically creates a snapshot with a timestamp. You can list these snapshots to see what the system preserved:
az netappfiles snapshot list \
--resource-group $RESOURCE_GROUP \
--account-name $NETAPP_ACCOUNT \
--pool-name $CAPACITY_POOL \
--volume-name $VOLUME_NAME \
--query "[?contains(name, 'ransomware')].{Name:name, Created:created, ProvisioningState:provisioningState}" \
-o table
The Azure portal provides more context about each threat—which files were flagged, what activity triggered the alert, and whether the pattern matches known ransomware behavior. You’ll need the portal to classify threats as false positives or confirmed attacks. The CLI doesn’t expose that functionality.
How to Respond to Detected Threats
When advanced ransomware protection detects suspicious activity, you need to evaluate whether it’s a real threat or a false positive. The Azure portal provides the threat details and classification interface—navigate to your NetApp volume, select Advanced Ransomware Protection from the sidebar, expand each threat to see flagged files, then mark as “False positive” or “Threat.”
But once you’ve confirmed a threat, you can handle recovery entirely from the CLI.
First, list available snapshots to find the one created during the attack:
az netappfiles snapshot list \
--resource-group $RESOURCE_GROUP \
--account-name $NETAPP_ACCOUNT \
--pool-name $CAPACITY_POOL \
--volume-name $VOLUME_NAME \
--query "[].{Name:name, Created:created}" \
-o table
Find the snapshot with a timestamp matching the threat alert, then revert the volume to that snapshot:
SNAPSHOT_ID=$(az netappfiles snapshot show \
--resource-group $RESOURCE_GROUP \
--account-name $NETAPP_ACCOUNT \
--pool-name $CAPACITY_POOL \
--volume-name $VOLUME_NAME \
--snapshot-name "snapshot-name-here" \
--query "id" -o tsv)
az netappfiles volume revert \
--resource-group $RESOURCE_GROUP \
--account-name $NETAPP_ACCOUNT \
--pool-name $CAPACITY_POOL \
--volume-name $VOLUME_NAME \
--snapshot-id $SNAPSHOT_ID
Wait for the revert operation to complete:
az netappfiles volume show \
--resource-group $RESOURCE_GROUP \
--account-name $NETAPP_ACCOUNT \
--pool-name $CAPACITY_POOL \
--name $VOLUME_NAME \
--query "{Name:name, ProvisioningState:provisioningState}" \
-o table
When ProvisioningState returns to Succeeded, your data is restored to the point right before the attack began.
Warning: Once you revert a volume, any changes made after the snapshot are lost. Confirm the threat before reverting.
When to Pause Protection
If you need to temporarily disable protection—for example, during a planned mass file migration that would trigger false positives—you can pause it from the portal. Navigate to your volume in the Azure portal, select Advanced Ransomware Protection, then click Pause Protection.
Resume protection the same way: navigate to your volume, select Advanced Ransomware Protection, click Resume Protection.
After resuming, the system rebuilds its behavioral profile over the next few hours. It observes your workload patterns again to establish a new baseline. You can verify protection status through the CLI:
az netappfiles volume show \
--resource-group $RESOURCE_GROUP \
--account-name $NETAPP_ACCOUNT \
--pool-name $CAPACITY_POOL \
--name $VOLUME_NAME \
--query "dataProtection" -o json
Performance Overhead You Need to Plan For
Machine learning analysis happens in real-time, which means computational overhead. Microsoft recommends enabling no more than five volumes per Azure region to mitigate performance issues. You should also increase QoS capacity by 5-10% to accommodate the monitoring overhead.
Check volume performance metrics after enabling protection to ensure latency stays within acceptable thresholds:
# Linux/WSL
az monitor metrics list \
--resource $(az netappfiles volume show \
--resource-group $RESOURCE_GROUP \
--account-name $NETAPP_ACCOUNT \
--pool-name $CAPACITY_POOL \
--name $VOLUME_NAME \
--query "id" -o tsv) \
--metric "AverageReadLatency" \
--start-time $(date -u -d '1 hour ago' '+%Y-%m-%dT%H:%M:%SZ') \
--end-time $(date -u '+%Y-%m-%dT%H:%M:%SZ') \
--interval PT1M \
--aggregation Average \
-o table
# macOS
az monitor metrics list \
--resource $(az netappfiles volume show \
--resource-group $RESOURCE_GROUP \
--account-name $NETAPP_ACCOUNT \
--pool-name $CAPACITY_POOL \
--name $VOLUME_NAME \
--query "id" -o tsv) \
--metric "AverageReadLatency" \
--start-time $(date -u -v-1H '+%Y-%m-%dT%H:%M:%SZ') \
--end-time $(date -u '+%Y-%m-%dT%H:%M:%SZ') \
--interval PT1M \
--aggregation Average \
-o table
If latency increases beyond what your applications can tolerate, you have three options: pause protection during critical operations, increase QoS allocation, or reconsider which volumes need protection most.
Deploy Protection Before You Need It
Your file shares are targets. Attackers know where they are, they know how valuable they are, and they’re actively trying to encrypt them. Hoping your firewall rules and MFA policies will stop every attack is optimistic at best.
Advanced ransomware protection gives you storage-level defense that doesn’t depend on perimeter security. Your volumes watch for actual encryption activity and stop it with automatic snapshots. Enable it on new volumes and it might be the difference between a minor incident and a catastrophic data loss event.
Test it in development. Understand the performance impact. Plan your migration strategy for existing volumes. Then deploy it to production before you need it. Because once ransomware starts encrypting your files, it’s too late to enable protection.
