Understanding the Publisher Rule Condition in AppLocker
Applies To: Windows 7, Windows 8, Windows Server 2008 R2, Windows Server 2012
This topic explains the AppLocker publisher rule condition, what controls are available, and how it is applied.
Publisher conditions can be made only for files that are digitally signed; this condition identifies an application based on its digital signature and extended attributes. The digital signature contains information about the company that created the application (the publisher). The extended attributes, which are obtained from the binary resource, contain the name of the product that the application is part of and the version number of the application. The publisher may be a software development company, such as Microsoft, or the Information Technology department of your organization.
Publisher conditions are easier to maintain than file hash conditions and are generally more secure than path conditions. Rules that are specified to the version level might have to be updated when a new version of the file is released. The following table describes the advantages and disadvantages of the publisher condition.
| Publisher condition advantages | Publisher condition disadvantages |
|---|---|
|
|
Wildcard characters can be used as values in the publisher rule fields according to the following specifications:
Publisher
The asterisk (*) character used by itself represents any publisher. When combined with any string value, the rule is limited to the publisher with a value in the signed certificate that matches the character string. In other words, the asterisk is not treated as a wildcard character if used with other characters in this field. For example, using the characters "M*" limits the publisher name to only a publisher with the name "M*." Using the characters "*x*" limits the publisher name only to the name “*x*”. A question mark (?) is not a valid wildcard character in this field.
Product name
The asterisk (*) character used by itself represents any product name. When combined with any string value, the rule is limited to the product of the publisher with a value in the signed certificate that matches the character string. In other words, the asterisk is not treated as a wildcard character if used with other characters in this field. A question mark (?) is not a valid wildcard character in this field.
File name
Either the asterisk (*) or question mark (?) characters used by themselves represent any and all file names. When combined with any string value, the string is matched with any file name containing that string.
File version
The asterisk (*) character used by itself represents any file version. If you want to limit the file version to a specific version or as a starting point, you can state the file version and then use the following options to apply limits:
Exactly. The rule applies only to this version of the application.
And above. The rule applies to this version and all later versions.
And Below. The rule applies to this version and all earlier versions.
The following table describes how a publisher condition is applied.
| Option | The publisher condition allows or denies… |
|---|---|
| All signed files |
All files that are signed by a publisher. |
Publisher only |
All files that are signed by the named publisher. |
Publisher and product name |
All files for the specified product that are signed by the named publisher. |
Publisher, product name, and file name |
Any version of the named file for the named product that is signed by the publisher. |
Publisher, product name, file name, and file version |
Exactly The specified version of the named file for the named product that is signed by the publisher. |
Publisher, product name, file name, and file version |
And above The specified version of the named file and any new releases for the product that are signed by the publisher. |
Publisher, product name, file name, and file version |
And below The specified version of the named file and any older versions for the product that are signed by the publisher. |
Custom |
You can edit the Publisher, Product name, File name, and Version fields to create a custom rule. |
For an overview of the three types of AppLocker rule conditions and explanations of the advantages and disadvantages of each, see Understanding AppLocker Rule Condition Types.