Breakout Process
BreakoutProcess is a sandbox setting in Sandboxie Ini, available since Sandboxie Plus 1.0.8 / Classic 5.55.8. It identifies an executable that may leave the current sandbox when a sandboxed process tries to start it.
The value is the executable's basename, such as viewer.exe. Matching is an exact, case-insensitive comparison. The current breakout implementation does not interpret * or ? as wildcards for this setting, and a full executable path is not supported as its value. SandMan's executable picker also stores the basename.
Host executable requirement
The service accepts a matching BreakoutProcess launch only if it can open and resolve the target executable as a host file outside the source sandbox's file root. An executable that resolves inside that root, a network/MUP path, or a target that cannot be opened or resolved does not pass this breakout check. This host-file validation is specific to BreakoutProcess; do not assume it applies to Breakout Folder.
Interaction with forced programs
Breakout does not guarantee an unsandboxed destination. After accepting the breakout rule, the service can find a matching Force Process or Force Folder rule in another enabled box and create the process there. If its check resolves back to the source box, the launch follows the normal sandboxed process-creation path instead. Do not rely on a fixed priority when multiple boxes could capture the process.
This setting affects future process launches, not a process already running in the sandbox. See Breakout Execution for the service validation, limited returned handles, security implications, and SandMan controls.