The purpose of this tool is to trace user inputs, in order to find injection points into sensitive methods (like java.lang.Runtime.exec, java.sql.Statement.executeQuery, ...) as well as the mutations on these inputs between the injection point and the method call.
"Marks" are generated, which must be inserted in every possible user input of your app. Different marks will help you determine the origin of an alert.
The list of monitored methods is available using the command > list_breakpoints in the CLI. This list can be modified with the > add_breakpoint and > delete_breakpoint commands.
Captain Hook Docker Main machine
container
┌────────────────────────────────────────┐ ┌────────────────────────────────────────┐
│ │ │ │
│ ┌─────────────────┐ ┌────────────────┐ │ │ ┌──────────────────────────┐ │
│ │ │ │ │ │ │ │ │ │
│ │ ┌────┐ │ │ Java Debugger │ │ │ │ │ │
│ │ │ │ Python │ │ ├─┼─────────────┼──────────► │ │
│ │ │ │ + │ │ │ │ │ │ Program being │ │
│ │ │ │ Frida │ │ │ │ JDWP │ │ analyzed │ │
│ │ │ │ │ │ ◄─┼─────────────┼──────────┤ │ │
│ │ │ │ ◄─┤ │ │ │ │ │ │
│ │ │ │ │ │ │ │ │ │ │ │
│ │ │CLI │ ├─► │ │ │ │ │ │
│ │ │ │ │ │ │ │ │ │ │ │
│ │ │ │ │ └────────────────┘ │ │ │ │ │
│ │ │ │ │ │ │ │ │ │
│ │ │ │ │ │ │ ┌──────┐ │ │ │
│ │ │ │ ├────────────────────┼─────────────┤►│frida-├─► │ │
│ │ │ │ │ │ │ │server◄─┤ │ │
│ │ └────┘ │ │ │ │ │ └──────────────────────────┘ │
│ │ │◄───────────────────┼─────────────┼─┤ │ │
│ └─────────────────┘ │ │ └──────┘ │
│ │ │ │
└────────────────────────────────────────┘ └────────────────────────────────────────┘
Its JVM must be launched with the following options:
-Xdebug-Xrunjdwp:transport=dt_socket,address=1000,server=y,suspend=n-Xint
Of course, the listening port (1000 in the above example) is arbitrary and can be changed.
If possible, install frida-server on the machine containing the program being analyzed, and launch it with the following command:
# frida-server -l 0.0.0.0:1500 &
The listening port / address can be changed as well to suit your needs.
At the end of the Dockerfile located in ./dbg, set the "host" (the machine running the program to analyze) IP address, the JDWP listening port and the Frida listening port (0 if frida-server is not available).
Then # make build, then # make run-dbg. Attach a second terminal to this container with # docker exec -it $(docker ps -lq) bash.
In the first one, run: cd debugger && make debug, then in the second one: cd frida && make instrument
You will be interacting with Captain Hook through the second terminal, presenting you with a CLI. Type > help for an exhaustive list of commands available, all documented.
## Experimental features
The "agent" folder is purely exerimental, as well as the > set_object_inspection_strategy command.