Microsoft Security Essentials Anti Virus

These definitions are updated once every 24 hours.

Sometimes you might want to update more often than once a day. This can be especially helpful if a particular piece of malware just won’t go away, no matter how many times your security software tries to clean it.

You can get the latest updates below.


Latest definitions

Antimalware and antispyware definitions

http://www.microsoft.com/security/portal/definitions/howtomse.aspx

 

These definitions are updated once every 24 hours.

Sometimes you might want to update more often than once a day. This can be especially helpful if a particular piece of malware just won’t go away, no matter how many times your security software tries to clean it.

You can get the latest updates below.


Latest definitions

Antimalware and antispyware definitions

http://www.microsoft.com/security/portal/definitions/howtomse.aspx

 

These definitions are updated once every 24 hours.

Sometimes you might want to update more often than once a day. This can be especially helpful if a particular piece of malware just won’t go away, no matter how many times your security software tries to clean it.

You can get the latest updates below.


Latest definitions

Antimalware and antispyware definitions

http://www.microsoft.com/security/portal/definitions/howtomse.aspx

 

These definitions are updated once every 24 hours.

Sometimes you might want to update more often than once a day. This can be especially helpful if a particular piece of malware just won’t go away, no matter how many times your security software tries to clean it.

You can get the latest updates below.


Latest definitions

Antimalware and antispyware definitions

http://www.microsoft.com/security/portal/definitions/howtomse.aspx

 

These definitions are updated once every 24 hours.

Sometimes you might want to update more often than once a day. This can be especially helpful if a particular piece of malware just won’t go away, no matter how many times your security software tries to clean it.

You can get the latest updates below.


Latest definitions

Antimalware and antispyware definitions

http://www.microsoft.com/security/portal/definitions/howtomse.aspx

 

These definitions are updated once every 24 hours.

Sometimes you might want to update more often than once a day. This can be especially helpful if a particular piece of malware just won’t go away, no matter how many times your security software tries to clean it.

You can get the latest updates below.


Latest definitions

Antimalware and antispyware definitions

http://www.microsoft.com/security/portal/definitions/howtomse.aspx

 

These definitions are updated once every 24 hours.

Sometimes you might want to update more often than once a day. This can be especially helpful if a particular piece of malware just won’t go away, no matter how many times your security software tries to clean it.

You can get the latest updates below.


Latest definitions

Antimalware and antispyware definitions

http://www.microsoft.com/security/portal/definitions/howtomse.aspx

 

These definitions are updated once every 24 hours.

Sometimes you might want to update more often than once a day. This can be especially helpful if a particular piece of malware just won’t go away, no matter how many times your security software tries to clean it.

You can get the latest updates below.


Latest definitions

Antimalware and antispyware definitions

http://www.microsoft.com/security/portal/definitions/howtomse.aspx

 

These definitions are updated once every 24 hours.

Sometimes you might want to update more often than once a day. This can be especially helpful if a particular piece of malware just won’t go away, no matter how many times your security software tries to clean it.

You can get the latest updates below.


Latest definitions

Antimalware and antispyware definitions

http://www.microsoft.com/security/portal/definitions/howtomse.aspx

 

These definitions are updated once every 24 hours.

Sometimes you might want to update more often than once a day. This can be especially helpful if a particular piece of malware just won’t go away, no matter how many times your security software tries to clean it.

You can get the latest updates below.


Latest definitions

Antimalware and antispyware definitions

http://www.microsoft.com/security/portal/definitions/howtomse.aspx

 

These definitions are updated once every 24 hours.

Sometimes you might want to update more often than once a day. This can be especially helpful if a particular piece of malware just won’t go away, no matter how many times your security software tries to clean it.

You can get the latest updates below.


Latest definitions

Antimalware and antispyware definitions

http://www.microsoft.com/security/portal/definitions/howtomse.aspx

 

These definitions are updated once every 24 hours.

Sometimes you might want to update more often than once a day. This can be especially helpful if a particular piece of malware just won’t go away, no matter how many times your security software tries to clean it.

You can get the latest updates below.


Latest definitions

Antimalware and antispyware definitions

http://www.microsoft.com/security/po.../howtomse.aspx
__________________

 

These definitions are updated once every 24 hours.

Sometimes you might want to update more often than once a day. This can be especially helpful if a particular piece of malware just won’t go away, no matter how many times your security software tries to clean it.

You can get the latest updates below.


Latest definitions

Antimalware and antispyware definitions

http://www.microsoft.com/security/po.../howtomse.aspx
__________________

 

These definitions are updated once every 24 hours.

Sometimes you might want to update more often than once a day. This can be especially helpful if a particular piece of malware just won’t go away, no matter how many times your security software tries to clean it.

You can get the latest updates below.


Latest definitions

Antimalware and antispyware definitions

http://www.microsoft.com/security/po.../howtomse.aspx
__________________

 

These definitions are updated once every 24 hours.

Sometimes you might want to update more often than once a day. This can be especially helpful if a particular piece of malware just won’t go away, no matter how many times your security software tries to clean it.

You can get the latest updates below.


Latest definitions

Antimalware and antispyware definitions

http://www.microsoft.com/security/po.../howtomse.aspx
__________________

 

Summary
Definition version

Virus: 1.203.968.0
Spyware: 1.203.968.0

Definition available date: (?)
Jul 31, 2015 10:01 PM UTC
http://www.microsoft.com/security/portal/definitions/whatsnew.aspx

 

Summary
Definition version

Virus: 1.205.1546.0
Spyware: 1.205.1546.0

Definition available date: (?)
Sep 03, 2015 09:55 PM UTC

Change definition version:
http://www.microsoft.com/security/portal/definitions/whatsnew.aspx

 

Summary
Definition version

Virus: 1.207.2155.0
Spyware: 1.207.2155.0

Definition available date: (?)
Oct 06, 2015 03:04 PM UTC
http://www.microsoft.com/security/portal/definitions/whatsnew.aspx

 

Summary
Definition version

Virus: 1.209.2210.0
Spyware: 1.209.2210.0


Definition available date: (?)
Nov 09,2015 09:12 PM UTC
http://www.microsoft.com/security/portal/definitions/whatsnew.aspx

 

Change log for version 1.211.2560.0
This page shows you what's changed in the most recent definitions update for Microsoft antimalware and antispyware software.

You can also see changes in the last 20 updates from the Change definition version menu on the right.

The latest update is:

• 1.211.2560.0

Download the latest update.

 

Antimalware and antispyware updates
For antimalware and antispyware, the latest definitions are 1.213.3147.0, dated Jan 16, 2016 11:18 PM UTC.
http://www.microsoft.com/security/portal/definitions/adl.aspx

 

Antimalware and antispyware updates
For antimalware and antispyware, the latest definitions are 1.213.6296.0, dated Feb 15, 2016 9:35 PM UTC.

To download these updates:

• Check whether your version of Windows is 32-bit or 64-bit.
• In the table below, right-click on the link that will work for your version of Windows and choose Save target as... or Save link as...
• Save the file to your Desktop.
• When the file has finished downloading, go to your Desktop and double-click the file (it will be calledmpam-fe.exe, mpas-fe.exe, or mpam-feX64.exe).
• Follow the prompts to install the update.

http://www.microsoft.com/security/portal/definitions/adl.aspx

 

Antimalware and antispyware updates
For antimalware and antispyware, the latest definitions are 1.215.1626.0, dated Mar 14, 2016 9:18 PM UTC.

• Check whether your version of Windows is 32-bit or 64-bit.
• In the table below, right-click on the link that will work for your version of Windows and choose Save target as... or Save link as...
• Save the file to your Desktop.
• When the file has finished downloading, go to your Desktop and double-click the file (it will be calledmpam-fe.exe, mpas-fe.exe, or mpam-feX64.exe).
• Follow the prompts to install the update.

http://www.microsoft.com/security/portal/definitions/adl.aspx

 

Antimalware and antispyware updates
For antimalware and antispyware, the latest definitions are 1.217.1273.0, dated Apr 13, 2016 10:22 PM UTC.

To download these updates:

• Check whether your version of Windows is 32-bit or 64-bit.

http://www.microsoft.com/security/portal/definitions/adl.aspx

 

Antimalware and antispyware updates
For antimalware and antispyware, the latest definitions are 1.219.1827.0, dated May 14, 2016 9:52 PM UTC.

To download these updates:

• Check whether your version of Windows is 32-bit or 64-bit.
• In the table below, right-click on the link that will work for your version of Windows and choose Save target as... or Save link as...
• Save the file to your Desktop.
• When the file has finished downloading, go to your Desktop and double-click the file (it will be calledmpam-fe.exe, mpas-fe.exe, or mpam-feX64.exe).
• Follow the prompts to install the update.

You can find out more about our products on the Microsoft security software page.
https://www.microsoft.com/security/portal/definitions/adl.aspx

 

Summary
Definition version

Virus: 1.223.675.0
Spyware: 1.223.675.0


Definition available date: (?)
Jun 03,2016 08:54 PM UTC

https://www.microsoft.com/security/portal/definitions/whatsnew.aspx

 

Change log for version 1.223.1196.0
This page shows you what's changed in the most recent definitions update for Microsoft antimalware and antispyware software.

You can also see changes in the last 20 updates from the Change definition version menu on the right.

The latest update is:

• 1.223.1196.0

Download the latest update.
https://www.microsoft.com/security/portal/definitions/whatsnew.aspx

 

Change log for version 1.225.1232.0
This page shows you what's changed in the most recent definitions update for Microsoft antimalware and antispyware software.

You can also see changes in the last 20 updates from the Change definition version menu on the right.

The latest update is:

• 1.225.1232.0

Download the latest update.
https://www.microsoft.com/security/portal/definitions/whatsnew.aspx

 

Change log for version 1.225.4092.0
This page shows you what's changed in the most recent definitions update for Microsoft antimalware and antispyware software.

You can also see changes in the last 20 updates from the Change definition version menu on the right.

The latest update is:

• 1.225.4092.0

Download the latest update.

https://www.microsoft.com/security/portal/definitions/whatsnew.aspx

 

Change log for version 1.227.2508.0
This page shows you what's changed in the most recent definitions update for Microsoft antimalware and antispyware software.

You can also see changes in the last 20 updates from the Change definition version menu on the right.

The latest update is:

• 1.227.2508.0

Download the latest update.
https://www.microsoft.com/security/portal/definitions/whatsnew.aspx

 

Change log for version 1.229.1319.0
This page shows you what's changed in the most recent definitions update for Microsoft antimalware and antispyware software.

You can also see changes in the last 20 updates from the Change definition version menu on the right.

The latest update is:

• 1.229.1319.0

Download the latest update.

https://www.microsoft.com/security/portal/definitions/whatsnew.aspx

 

• Change log for version 1.231.908.0
  This page shows you what's changed in the most recent definitions update for Microsoft antimalware and antispyware software.
  
  You can also see changes in the last 20 updates from the Change definition version menu on the right.
  
  The latest update is:
  
  • 1.231.1283.0
  Summary
  Definition version
  
  Virus: 1.231.908.0
  Spyware: 1.231.908.0
  
  
  Definition available date:
  Nov 01,2016 11:26 AM UTCDownload the latest update.

 

Antimalware and antispyware updates
For antimalware and antispyware, the latest definitions are 1.233.1637.0, dated Dec 7, 2016 9:57 PM UTC.
https://www.microsoft.com/en-us/security/portal/definitions/adl.aspx

 

Antimalware and antispyware updates
For antimalware and antispyware, the latest definitions are 1.233.4036.0, dated Jan 5, 2017 10:51 PM UTC.
https://www.microsoft.com/en-us/security/portal/definitions/adl.aspx

 

Summary
Definition version

Virus: 1.235.2025.0
Spyware: 1.235.2025.0


Definition available date:
Feb 03,2017 10:06 PM UTC
https://www.microsoft.com/en-us/security/portal/definitions/adl.aspx

 

Change log for version 1.235.3124.0
This page shows you what's changed in the most recent definitions update for Microsoft antimalware and antispyware software.

You can also see changes in the last 20 updates from the Change definition version menu on the right.

The latest update is:

• 1.235.3124.0

Download the latest update.

 

Summary
Definition version

Virus: 1.237.1001.0
Spyware: 1.237.1001.0


Definition available date:
Mar 10,2017 09:27 PM UTC

https://www.microsoft.com/en-us/security/portal/definitions/whatsnew.aspx

 

Change log for version 1.239.1217.0
This page shows you what's changed in the most recent definitions update for Microsoft antimalware and antispyware software.

You can also see changes in the last 20 updates from the Change definition version menu on the right.

The latest update is:

Summary
Definition version

Virus: 1.239.1217.0
Spyware: 1.239.1217.0


Definition available date:
Apr 10,2017 07:39 PM UTC

https://www.microsoft.com/en-us/security/portal/definitions/whatsnew.aspx

 

Change log for version 1.243.219.0
This page shows you what's changed in the most recent definitions update for Microsoft antimalware and antispyware software.

You can also see changes in the last 20 updates from the Change definition version menu on the right.

The latest update is:

• 1.243.219.0

Download the latest update.
https://www.microsoft.com/en-us/security/portal/definitions/whatsnew.aspx

 

Summary
Definition version

Virus: 1.247.74.0
Spyware: 1.247.74.0


Definition available date:
Jun 24,2017 10:12 PM UTC
https://www.microsoft.com/en-us/security/portal/definitions/whatsnew.aspx

 

Change log for version 1.249.219.0
This page shows you what's changed in the most recent definitions update for Microsoft antimalware and antispyware software.

The latest update is:

• 1.249.219.0

Download the latest update.
https://www.microsoft.com/en-us/security/portal/definitions/whatsnew.aspx

 

Latest definitions
The latest antimalware definitions file is as follows:

• Version: 1.249.1289.0
• Released: Aug 20,2017 07:58 PM UTC
• Documentation: Release notes

https://www.microsoft.com/en-us/wdsi/definitions/antimalware-definition-release-notes

 

Change log for version 1.251.1326.0
This page shows you what's changed in the most recent definitions update for Microsoft antimalware and antispyware software.

The latest update is:

• 1.251.1326.0

Download the latest update.

Select change log
The following tables list the new and updated definitions for the version you select here. You can choose from the 20 latest updates, and the most recent update is shown by default:


Definition available date: Sep 22,2017 08:41 PM UTC
https://www.microsoft.com/en-us/wdsi/definitions/antimalware-definition-release-notes

 

Change log for version 1.253.736.0
This page shows you what's changed in the most recent definitions update for Microsoft antimalware and antispyware software.

The latest update is:

• 1.253.736.0

Download the latest update.

https://www.microsoft.com/en-us/wdsi/definitions/antimalware-definition-release-notes

 

Change log for version 1.257.313.0
This page shows you what's changed in the most recent definitions update for Microsoft antimalware and antispyware software.

The latest update is:

• 1.257.313.0

Download the latest update.

Select change log
The following tables list the new and updated definitions for the version you select here. You can choose from the 20 latest updates, and the most recent update is shown by default:

Definition available date: Nov 10,2017 10:20 AM UTC
https://www.microsoft.com/en-us/wdsi/definitions/antimalware-definition-release-notes

 

Change log for version 1.257.1466.0
This page shows you what's changed in the most recent definitions update for Microsoft antimalware and antispyware software.

The latest update is:

• 1.259.42.0

Download the latest update.

Select change log
The following tables list the new and updated definitions for the version you select here. You can choose from the 20 latest updates, and the most recent update is shown by default:


Definition available date: Dec 06,2017 05:03 PM UTC
https://www.microsoft.com/en-us/wdsi/definitions/antimalware-definition-release-notes

 

Download the latest update

Select change log
The following tables list the new and updated definitions for the version you select here. You can choose from the 20 latest updates, and the most recent update is shown by default:


Definition available date: Jan 02,2018 07:06 PM UTC
https://www.microsoft.com/en-us/wdsi/definitions/antimalware-definition-release-notes

 

Change log for definition version 1.261.416.0
This page lists what has changed in the most recent definitions update for Windows Defender Antivirus and Microsoft Security Essentials.

If this page does not show change logs for the latest update (1.261.416.0), please try hitting refresh or let us know through the feedback link at the bottom of this page.

Download the latest update

Select change log
The following tables list the new and updated definitions for the version you select here. You can choose from the 20 latest updates, and the most recent update is shown by default:


Definition available date: Jan 28,2018 08:07 PM UTC
https://www.microsoft.com/en-us/wdsi/definitions/antimalware-definition-release-notes

 

Change log for definition version 1.261.1721.0
This page lists what has changed in the most recent definitions update for Windows Defender Antivirus and Microsoft Security Essentials.

If this page does not show change logs for the latest update (1.263.51.0), please try hitting refresh or let us know through the feedback link at the bottom of this page.

Download the latest update

Select change log
The following tables list the new and updated definitions for the version you select here. You can choose from the 20 latest updates, and the most recent update is shown by default:


Definition available date: Feb 28, 2018 05:08 PM UTC
https://www.microsoft.com/en-us/wdsi/definitions/antimalware-definition-release-notes

 

Latest definitions
The latest antimalware definitions file is as follows:

• Version: 1.263.1728.0
• Released: Mar 29, 2018 09:03 PM UTC
• Documentation: Release notes

https://www.microsoft.com/en-us/wdsi/definitions