About File Blocking Parent topic

The File Blocking feature of IM Security allows you to:
  • Prevent the exchange of files between users based on specified file properties (file size, file name, extension, true file type)
  • Save network bandwidth by limiting the size of files being transferred across IM Security servers through the default invitation layer rule
Enable File Blocking to evaluate files based on Trend Micro or user-defined rules.
IM Security provides the following default rules.
Default Rules
Default Settings
Default file size rule
  • Works at the invitation layer (before IM Security downloads the file)
  • Cannot be deleted
  • Filter files according to file size
  • Action = Cancel file transfer
Default file extension rule
  • Works at the transfer layer (after IM Security downloads the file)
  • Can be deleted
  • Filter files according to file extension name
  • Action = Cancel file transfer
  • Depending on your Windows Messenger version and Service Pack installed, some extension names are automatically blocked at the invitation layer. Refer to Windows Messenger documentation for details.
File Blocking works by determining a file's properties (size, type, and name). Once it determines the file's properties, it then compares them with the values specified for each rule. If one of the file's properties matches a value specified in a rule, IM Security takes the administrator specified action on the file. IM Security also sends notifications to administrator specified recipients whenever it takes action.