Hijack allows you to connect to any ruby process and execute code as if it were a normal irb session. Hijack does not require your target process to require any hijacking code, hijack is able to connect to any ruby process. It achieves this by using gdb to inject a payload into the process which starts up a DRb server, hijack then detaches gdb and reconnects via DRb. Please note that gdb will halt your target process while it is attached, though the injection process is very quick and your process should only be halted for a few milliseconds. Hijack uses DRb over a unix socket file, so you need to be on the same machine as the process you want to hijack. This is by design for security reasons. You also need to run the hijack client as the same user as the remote process.