August 2015 anti-malware platform update for Windows Defender in Windows 8.1 and Windows 8

Applies to: Windows 8.1 EnterpriseWindows 8.1 ProWindows 8.1
This anti-malware platform update for Windows Defender updates Windows Defender services, drivers, and UIs in Windows RT 8.1, Windows 8.1, Windows RT, and Windows 8. This update has prerequisites.

Microsoft regularly releases anti-malware platform updates to guarantee consistency in protection, performance, robustness, and usability in a malware landscape that is constantly changing.

About this update

This anti-malware platform update contains the following improvements:
  • Reduces network traffic when signatures are fetched from Universal Naming Convention (UNC) shares
  • Updates to improve existing functionality to the anti-malware platform

How to obtain this update

Method 1: Windows Update

This update is available on Windows Update. For more information on how to run Windows Update, see How to get an update through Windows Update.

Method 2: Microsoft Download Center

The following files are available for download from the Microsoft Download Center:
Operating systemUpdate
All supported x86-based versions of Windows 8.1Download Download the package now.
All supported x64-based versions of Windows 8.1 Download Download the package now.
All supported x86-based versions of Windows 8Download Download the package now.
All supported x64-based versions of Windows 8 Download Download the package now.
Note The update for Windows RT 8.1 or Windows RT can be obtained only from Windows Update.

For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to obtain Microsoft support files from online services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.

Update detail information

Prerequisites

To apply this update for Windows 8.1 and Windows RT 8.1, you must install April 2014 update rollup for Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 (2919355).

Registry information

To use the update in this package, you do not have to make any changes to the registry.

Restart requirement

You may have to restart the computer after you apply this update.

Update replacement information

This update does not replace a previously released update.

References

See the terminology that Microsoft uses to describe software updates.