The World's Most Advanced Sandbox™

The World’s Most Advanced Sandbox™ (TWMAS) is a portable sandbox designed to safely run untrusted Java bytecode. Unlike traditional sandboxes, many of which use non-portable operating system (OS) facilities to run the untrusted code in a separate process with restricted privileges, TWMAS does not make use of the OS. Rather, it provides a way for a host Java Virtual Machine (JVM) to execute untrusted code directly, using the Java SecurityManager to block access to dangerous capabilities (Filesystem, Network, System, etc.) and instruction-rewriting in order to bound the number of bytes of memory allocated and the number of instruction executed.

A full explanation can be found here

The bulk of the functionality is in code is in src/sandbox:

src/main/sandbox/agent contains the code for attaching an javaagent to the JVM on startup.
src/main/sandbox/classloader contains a custom classloader that measures the size of different objects
src/main/sandbox/instrumentation contains the code which using the ASM bytecode library to instrument the bytecode
src/main/sandbox/runtime contains the classes needed at run-time to support the functionality of the sandbox (e.g. the method calls which account for instruction/memory usage)
src/test/sandbox contains the test script which runs the unit tests and exercises the functionality of the sandbox
resources contains the Java source files for our demo applications which are exercised by our tests and referenced in our report.