VMware Carbon Black App Control Windows Agent 8.7.6 Release Notes

VMware Carbon Black App Control 8.7.6 \| 09 JUN 2022 \| Build 8.7.6.716.340 Check for additions and updates to these release notes.

VMware Carbon Black App Control 8.7.6 | 09 JUN 2022 | Build 8.7.6.716.340

Check for additions and updates to these release notes.

What's New

This document provides change information and installation instructions for VMware Carbon Black App Control v8.7.6 Windows Agents.

This maintenance release addresses an issue that can lead to rules being improperly enforced on Windows when the SHA256 macro is used. VMware Carbon Black recommends updating to this version of the Windows agent (or later) or if that is not possible, disabling rules that utilize the SHA256 macro.

Installation Instructions

As of the 8.1.4 server release, the Windows Agent no longer comes bundled with the VMware Carbon Black App Control Server, nor does it require manual (command line) steps to add it to the server.

You can upgrade Carbon Black App Control Windows Agents without having to upgrade the Carbon Black App Control Server. Please see the latest Carbon Black App Control User Guide for more information.

NOTE: This Windows Agent is compatible with App Control Server version 8.1.4 and subsequent releases

For information regarding which Windows operating systems are supported in this release, please review the respective Windows Agent OER:

Resolved Issues

The following issues were resolved in this release.

EP-15650: Fixed an issue which caused SHA256 macros to improperly enforce rules. (EA-21222)

Known Issues

EP-1201: On Windows 2003 x64, you may see a health check reporting improper classifications immediately after installation

This should go away after roughly fifteen minutes.
EP-1682: Carbon Black App Control does not support in-container enforcement

Users can use the Microsoft Edge Virtualization feature, but Carbon Black App Control will not enforce rules within the container. It will, however, enforce rules on anything that breaks out of the sandbox.
EP-2393: The appearance in the console of block and report events related to the Ransomware rapid config may be delayed by a minute or more
EP-5483: The agent currently tracks all the extracted content from the Windows 10 WIM image in the temp directory

A rule to ignore these writes is not yet functioning properly.
EP-5498: In some cases, the agent will report an empty installer for a given file

The file will still be correctly approved or not, as expected on the endpoint. Only reporting of the source installer is failing, not enforcement of relevant rules.
EP-6982: Carbon Black App Control does not support NTFS reparse points as exclusion paths and they should not be used with kernelFileOpExclusions configuration rules

Reparse points include such objects like symbolic links, directory junction points and volume mount points.
EP-6104: Cleanmgr.exe is a windows utility process that runs occasionally and will copy files to the "temp" folder in order to run analysis on them

These files are only copies of other files already on the machine and cleanmgr.exe never executes them.
EP-6106: An installation of a new Carbon Black App Control Agent on the latest version of Windows 10 can result in a health check error due to a miscalculation of how many events the agent should send to the Carbon Black App Control server

This problem disappears after a reboot.
EP-6107: After upgrading agents on Windows XP systems, it is possible to see signature error events stating that the installer download failed

The upgrade should be successful and there should not be any impact on the upgrade process.
EP-6197: Occasionally the agent will complain about metadata not being properly populated and trigger an Error

The Error implies a mismatch in expectation but is not expected to break functionality of the agent and can be ignored.

EP-10542: When uninstalling the agent, a Carbon Black App Control Agent dialog displays informing the user that certain applications must be closed before continuing the installation

This informational message is caused by a known msiexec defect.

Important: This could occur during a removal of the agent using "add/remove programs" or during an upgrade of the agent if you are using 3rd party software or a manual upgrade using msiexec. Customers that perform agent upgrades from within the Carbon Black App Control Admin console are not affected. When uninstalling the agent or performing a manual upgrade, or upgrade using 3rd party software, you can suppress this dialog with the additional msiexec command line argument "/qb-". This will disable modal dialog during manual uninstalls and upgrades.

Important: This could occur during a removal of the agent using "add/remove programs" or during an upgrade of the agent if you are using 3rd party software or a manual upgrade using msiexec.

Customers that perform agent upgrades from within the Carbon Black App Control Admin console are not affected.

When uninstalling the agent or performing a manual upgrade, or upgrade using 3rd party software, you can suppress this dialog with the additional msiexec command line argument "/qb-". This will disable modal dialog during manual uninstalls and upgrades.

The example below shows how to manually uninstall the Carbon Black App Control agent with the /qb- argument:

msiexec /x {9F2D4E59-0528-4B22-B664-A6B0B8B482EE} /qb-

This issue is not new to the Windows agent and possibly affected customers on earlier releases. A long term fix will be implemented in a future release.

Upgrade Issue with Windows XP and Server 2003

Windows XP and Server 2003 lack the necessary certificates (both root and intermediate) to validate the timestamps in the signature we use. In order to upgrade these operating systems to 8.7.4 of the App Control agent customers will need to choose to do one of the following:

Option 1: Import the Missing Certificates Into the Computer Certificate Store

You can download the necessary certificates from https://community.carbonblack.com/t5/Documentation-Downloads/App-Control-Windows-Agent-Digicert-Timestamp/ta-p/112610.

Install the certificates on your machines either directly using MMC with the Certificates snap-in or use GPO. The root certificate should be imported to the Trusted Root Certification Authorities store. The intermediate certificate should go to the Intermediate Certification Authorities store. These should be imported at the machine level as opposed to the user level.

Option 2: Explicitly Trust the Timestamping Publisher

Another option is to trust the timestamping certificate. This can be a bit challenging because it requires querying the database for the correct id. Full instructions can be found on this document: https://community.carbonblack.com/t5/App-Control-Discussions/Ineligible-for-Approval-CERT-TRUST-IS-PARTIAL-CHAIN/m-p/68553/thread-id/6292

Option 3: Use the ignore_partial_chain_on_countersignatures config prop

Agents can be configured to ignore the missing countersignatures. This allows approval by publisher for files that have valid code signing chains, while ignoring errors on the counter signing chain.

Details on how to configure this can be found here:

https://community.carbonblack.com/t5/Knowledge-Base/App-Control-How-can-I-ignore-partial-cert-chain-errors/ta-p/73892

Please note that if the root certificate is not trusted (using Option 1 or 2), this method will still result in the following error: CERT_TRUST_IS_UNTRUSTED_ROOT.