Adjust Process Security is an action that allows a process to be protected from tampering by users.
The existing Adjust Process Rights [[Security]] action in v8.0 would elevate the integrity level of processes if an integrity level SID was specified, but would not lower the integrity level in “decrease mode”. This feature has been implemented. [[Meaning it now will lower the integrity level in "Decrease Mode"?]]
Restricted SIDs
As well a less well known (and used) feature has been added: Restricted SIDs. This feature is just exposed as an option “Restricted Code” on the Adjust Process Rights action.
The main intended usage of Restricted SIDs is the Well Known SID RESTRICTED_CODE (RESTRICTED). Technically when evaluating security for any operation, when there is any Restricted SID specified then not only does the Security Descriptor need to allow access to the user, but also explicitly to the Restricting SID.
Generally in usage this mechanism basically removes all ability for a program to execute at all. Microsoft recognised the practical limitations of this mechanism and introduced a tweak that only applies the Restricted SID functionality to WRITE operations. Our Restricted Process option leverages this functionality.
So whilst a Restricted Process would be able to read any local resources the user could read (unless banned by deny Security Descriptors), any ability to write to resources is protected.
Another benefit of this is that Restricted Processes When you remove administrative rights for applications using the remove administrative rights action, there is an advanced feature that allows you to apply restricted Security Identifiers (SIDs), which further restricts access to securable objects.
What is a restricted SID?
A restricted ID is an access token that modifies a user's access to securable objects and controls a user's ability to perform various system-related operations on the local computer.
When a restricted process or thread tries to access a securable object, the system performs two access checks: one using the token's enabled SIDs, and another using the list of restricted SIDs. Access is granted only if both access checks allow the requested access rights. (For more information about restricted SIDs, go to the Microsoft Developer Network Library at https://msdn.microsoft.com/en-us/library/windows/desktop/aa379316(v=vs.85).aspx.)
When to use restricted ID
Use a restricted SID to further restrict the applications in the sandbox, which you can use as another method of orangelisting. In other words, this is a way to protect yourself against unknown applications if you don't want to implement blacklisting.
The restricted SID will allow only Read access to the user registry but not to the local machine registry. Also, restricted processes do not have rights to open any network based resource (e.g., file servers).-based resource, such as file servers. As a result, the restricted SID will be able to do very little and apps may not work correctly under this model. Ultimately, apps in the sandbox that have restricted SID applied to them will be severely locked down.
Apply restricted SID
To apply restricted SID, do the following steps:
- In the Thycotic Security Manager, click the Policies tab.
- In the file library in the left pane, navigate to Thycotic Solutions > Application Control > Actions > Process Rights > Remove Administrative Rights.
- In the right pane under Action Type, select the Apply Restricted SID (advanced) check box.
- Click the Save button.
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