The recently released hotfixes KB2735855 and KB2750841 have been confirmed to cause data corruption during the download when a 3rd party driver working at Windows Filtering Platform layer intervenes in the communication. ESET has demonstrated it using a sample driver from Windows Development Kit and will contact Microsoft to address the issue with as highest priority as possible. In the mean time, we strongly recommend removing this hotfix until Microsoft comes up with a solution. Update: Microsoft has released hotfix 2789397 addressing this issue. Discussion on this topic is allowed in this thread.