The objective of NSX Intrusion Detection and Prevention Service (IDS/IPS) is to monitor network traffic on the hosts and edges for malicious activity by comparing the traffic against a known set of signatures. The objective of NSX Malware Prevention is to extract files from the network traffic on the hosts and edges and analyze these files for malicious behavior.

Overview of NSX Intrusion Detection and Prevention Service

NSX IDS/IPS monitors network traffic on a host for suspicious activity by comparing the traffic against signatures. A signature specifies a pattern for a type of network intrusion that needs to be detected and reported. Whenever a matching traffic pattern to a signature is found, a predefined action is taken, such as generating an alert or blocking the traffic from reaching its destination.

NSX Data Center supports IDS/IPS capability on the following firewalls:
  • Distributed Firewall: Prior to NSX Data Center 3.2, implementation of IDS was limited to knowledge-based signatures. Knowledge-based signatures incorporate specific knowledge or pattern that corresponds to a known type of attack. In this approach, IDS attempts to detect intrusions based on already known malicious instruction sequences specified in signatures. Thus, knowledge-based signatures are limited to attacks that are already known and cannot cover targeted or zero-day threats.

    Starting with NSX Data Center 3.2, IDS also supports behavior-based detection. Behaviour-based detection attempts to identify anomalous behaviour by pinpointing interesting events that are different or unusual compared to a baseline or normal traffic.

    These events are called informational or info and consists of events that pinpoint unusual activities in a network that are not necessarily malicious but can provide valuable information when investigating a breach. Signatures are bundled together with custom detection logic that can be updated without having to recompile or modify the IDS engine. Behavior-based detection introduces a new IDS intrusion severity level as 'suspicious'.

  • Gateway Firewall: Starting with NSX Data Center 3.2, IDS/IPS is also available on Gateway Firewall.
    Important: In NSX-T Data Center 3.2.0, NSX IDS/IPS on Gateway Firewall was available in tech preview mode only. Starting with NSX-T Data Center 3.2.1, this feature is available for production environments and has full support. For more information, see the NSX-T Data Center Release Notes.

Overview of NSX Malware Prevention

NSX Malware Prevention can detect and prevent known malicious files and unknown malicious files. Unknown malicious files are also referred to as zero-day threats. To detect malware, NSX Malware Prevention uses a combination of the following techniques :
  • Hash-based detection of known malicious files
  • Local analysis of unknown files
  • Cloud analysis of unknown files
Note: In NSX-T Data Center 3.2, NSX Malware Prevention supports the following capabilities:
  • On the Gateway Firewall, only detection of malware is supported. Both local analysis and cloud analysis of malware files is supported. To view the list of supported file categories, see File Categories Supported for NSX Malware Prevention.
  • On the Distributed Firewall, malware detection and prevention is supported only for Windows guest endpoints (VMs) running on vSphere host clusters that are prepared for NSX. Only Windows Portable Executable (PE) files are supported for local analysis and cloud analysis. Other file categories are not supported currently by NSX Distributed Malware Prevention.
  • The supported maximum file size limit is 64 MB.

Conceptual overview of NSX Malware Prevention in an NSX-T Data Center.

On the north-south traffic, the NSX Malware Prevention feature uses the IDS/IPS engine on the NSX Edges to extract or intercept the files that are entering the data center. On the east-west traffic, this feature uses the capabilities of the NSX Guest Introspection (GI) platform. If the file bypasses scrutiny on the NSX Edge and reaches the host, the file is extracted by the GI thin agent on Windows guest VMs.

To detect and prevent malware on Windows guest VMs, you must deploy the NSX Distributed Malware Prevention service on vSphere host clusters that are prepared for NSX. When this service is deployed, a service virtual machine (SVM) is installed on each host of the vSphere cluster and NSX Malware Prevention is enabled on the host cluster.