Understanding the File Hash Rule Condition in AppLocker
Updated: June 21, 2012
Applies To: Windows 7, Windows 8.1, Windows Server 2008 R2, Windows Server 2012 R2, Windows Server 2012, Windows 8
This topic explains the AppLocker file hash rule condition, the advantages and disadvantages, and how it is applied.
File hash rules use a system-computed cryptographic hash of the identified file. For files that are not digitally signed, file hash rules are more secure than path rules. The following table describes the advantages and disadvantages of the file hash condition.
File hash condition advantages
File hash condition disadvantages
Because each file has a unique hash, a file hash condition applies to only one file.
Each time that the file is updated (such as a security update or upgrade), the file's hash will change. As a result, you must manually update file hash rules.
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.