As Adobe announced, Adobe Acrobat XI went end of life already on October 15th 2017. Application has been active in CSM because of possible updates. Some of our customers have application still enabled on CSM. However, it's quite unlikely, that new versions will be published anymore. This is why we recommend you to check if you have Adobe Acrobat XI enabled on CSM and consider if it should be disabled. It's highly recommended to use Adobe Reader DC instead of XI. You can enable DC on CSM in CSM management portal.