sogen 0.0.1.dev4729

Sogen Windows user-space emulator bindings

Sogen exposes Python bindings for Windows and Linux userspace emulation. The Python API is meant for scripting runs, building small analysis helpers, and quickly iterating on callbacks; Windows bindings also expose hooks for deeper analysis.

Install from PyPI:

pip install sogen

Project links:

• PyPI: https://pypi.org/project/sogen/
• Repository: https://github.com/momo5502/sogen
• Ready-made emulation root: https://sogen.dev/root.zip

What you need

The Python package still needs an emulation root at runtime. Download ready-made root here:

• https://sogen.dev/root.zip

Extract it somewhere convenient, for example:

./root

Most examples in this document use:

emulation_root="./root"

Quick start

import sogen

app = sogen.windows.create_application(
    "c:/test-sample.exe",
    emulation_root="./root",
)

app.callbacks.on_stdout = lambda text: print(text, end="")
app.start()
print("exit status:", app.process.exit_status)

Linux quick start:

import sogen

syscalls = []


def on_syscall(syscall_id, syscall_name):
    syscalls.append((syscall_id, syscall_name))
    return sogen.HookContinuation.run


app = sogen.linux.create_application(
    "/bin/true",
    emulation_root="/",
    backend=sogen.Backend.unicorn,
)

app.callbacks.on_syscall = on_syscall
app.start()
print("exit status:", app.process.exit_status)
print("syscalls observed:", len(syscalls))

sogen.linux exposes its own Linux-scoped factories, including sogen.linux.create_application(...) and sogen.linux.create_empty(...); it does not use the root-level compatibility aliases.

Minimal example with file + port mappings

Windows example:

from pathlib import Path
import sogen

app = sogen.windows.create_application(
    "c:/test-sample.exe",
    emulation_root="./root",
    path_mappings={"c:/a.txt": Path("./a.txt")},
    port_mappings={28970: 28980},
)

app.callbacks.on_stdout = lambda text: print(text, end="")
app.start()
print("exit status:", app.process.exit_status)

Linux applications also accept guest cwd, filesystem mapping, and TCP port mapping kwargs:

from pathlib import Path
import sogen

app = sogen.linux.create_application(
    "/bin/my-tool",
    emulation_root="./linux-root",
    working_directory="/work",
    path_mappings={"/work/input": Path("./fixtures/input")},
    read_only_path_mappings=[("/work/readonly", Path("./fixtures/readonly"))],
    port_mappings={8080: 18080},
)

assert app.get_host_port(8080) == 18080
assert app.get_emulator_port(18080) == 8080

Linux working_directory is normalized as an absolute guest path and is active before application load/startup, so it applies to interpreter/loader work as well as getcwd() and cwd-relative syscalls such as open() and openat(AT_FDCWD, ...). path_mappings and read_only_path_mappings are also installed before load/startup, making mapped guest paths visible to interpreter startup and later filesystem operations. They accept either {guest_path: host_path} dictionaries or [(guest_path, host_path), ...] sequences, and the longest matching guest prefix wins. Read-only mappings reject mutating file operations including write-open, write, truncate, chmod, unlink, and rename. port_mappings accepts {emulator_port: host_port} or [(emulator_port, host_port), ...]; mapped IPv4 loopback TCP connect() calls are proxied to the configured host loopback port, while unmapped ports keep the synthetic Linux socket behavior.

Path and port mappings explicitly opt into host filesystem and network access. They are convenience bridges for tests and controlled analysis workflows, not a malware sandbox boundary.

Choosing backend

sogen.windows.create_empty(), sogen.windows.create_application(), sogen.linux.create_empty(), and sogen.linux.create_application() accept backend=sogen.Backend.unicorn.

import sogen

emu = sogen.windows.create_empty(
    emulation_root="./root",
    backend=sogen.Backend.unicorn,
)

Available values:

• sogen.Backend.unicorn
• sogen.Backend.icicle
• sogen.Backend.whp (Windows)
• sogen.Backend.kvm (Linux x86_64)

Default is sogen.Backend.unicorn.

High-level structure

Windows entry points:

• sogen.windows.create_empty(...)
• sogen.windows.create_application(...)

Linux entry points:

• sogen.linux.create_empty(...)
• sogen.linux.create_application(...)

Windows compatibility aliases currently remain at top level and are Windows-specific:

• sogen.create_empty(...) -> sogen.windows.create_empty(...)
• sogen.create_application(...) -> sogen.windows.create_application(...)

Objects exposed by the Windows bindings:

• sogen.windows.Emulator / sogen.windows.WindowsEmulator
• ProcessContext
• Thread
• MemoryManager
• Hooks
• Callbacks

Linux-specific objects exposed by the bindings:

• sogen.linux.Emulator / sogen.linux.LinuxEmulator
• sogen.linux.ProcessContext
• sogen.linux.MemoryManager
• sogen.linux.Thread
• sogen.linux.MemoryRegionInfo
• sogen.linux.Hook
• sogen.linux.Hooks
• sogen.linux.Callbacks
• sogen.linux.ExportedSymbol
• sogen.linux.MappedSection
• sogen.linux.LinuxMappedModule
• sogen.linux.SymbolHooks
• sogen.linux.LinuxSymbolCall
• sogen.linux.ThreadWaitState

Linux callback slots:

• app.callbacks.on_stdout
• app.callbacks.on_stderr
• app.callbacks.on_syscall
• app.callbacks.on_memory_violate
• app.callbacks.on_memory_allocate
• app.callbacks.on_memory_protect
• app.callbacks.on_memory_release
• app.callbacks.on_module_load
• app.callbacks.on_thread_create
• app.callbacks.on_thread_terminated
• app.callbacks.on_thread_switch

Common Windows workflows:

• run application with app.start()
• watch output with app.callbacks.on_stdout
• react to module loads with app.callbacks.on_module_load
• intercept WinAPI calls with app.hooks.apis[...]
• read/write emulator memory with read_memory() / write_memory()
• save and restore state with save_snapshot() / restore_snapshot()

Callbacks

Example: print loaded modules.

import sogen

app = sogen.windows.create_application(
    "c:/test-sample.exe",
    emulation_root="./root",
)


def on_module_load(module):
    print(f"loaded {module.name} @ 0x{module.entry_point:x}")


app.callbacks.on_module_load = on_module_load
app.start()

Useful Linux callback slots:

• app.callbacks.on_stdout
• app.callbacks.on_stderr
• app.callbacks.on_syscall
• app.callbacks.on_memory_violate
• app.callbacks.on_memory_allocate
• app.callbacks.on_memory_protect
• app.callbacks.on_memory_release
• app.callbacks.on_module_load
• app.callbacks.on_thread_create
• app.callbacks.on_thread_terminated
• app.callbacks.on_thread_switch

Useful Windows callback slots:

• app.callbacks.on_stdout
• app.callbacks.on_syscall
• app.callbacks.on_memory_violate
• app.callbacks.on_module_load
• app.callbacks.on_module_unload

Linux on_syscall callbacks use callback(syscall_id: int, syscall_name: str) -> sogen.HookContinuation | bool | None. None, False, and sogen.HookContinuation.run continue the built-in syscall handler. True and sogen.HookContinuation.skip suppress the built-in handler, so an intercepting callback must update guest registers and memory itself.

Linux on_module_load callbacks use callback(module: sogen.linux.LinuxMappedModule) -> None. Assigning app.callbacks.on_module_load replays modules already mapped during application construction in ascending image-base order, then observes future ELF modules discovered from runtime file-backed mmap() activity (for example libc mapped by the Linux dynamic loader). Linux currently exposes no module-unload callback because there is no native Linux unload event source in the emulator.

Linux thread controls expose the active emulated thread and cooperative native scheduler hooks:

• app.current_thread returns the active sogen.linux.Thread or None.
• app.current_thread_id returns the active TID or None.
• app.activate_thread(tid) switches to a live thread, saving/restoring CPU registers, and returns False for missing or terminated threads.
• app.perform_thread_switch() chooses the next runnable non-terminated thread in TID order and returns whether a switch happened.
• app.yield_thread() performs that switch and stops the backend if it switched.
• app.process.threads lists non-terminated Linux threads; each thread exposes tid, current_ip, start_address, wait_state, setup_done, stack/TLS fields, termination state, exit code, and executed-instruction count. previous_ip raises NotImplementedError until Linux tracks a prior instruction pointer instead of silently returning a placeholder value.

Linux thread callbacks use native lifecycle/switch paths:

• app.callbacks.on_thread_create(thread) fires after clone(CLONE_THREAD) creates a thread.
• app.callbacks.on_thread_terminated(thread) fires when a Linux thread exits.
• app.callbacks.on_thread_switch(old_tid, new_tid) fires when the active TID changes through activate_thread() or the scheduler.

Linux emulators expose stop diagnostics after every start() call:

• app.last_stop_reason is a string: "none", "unknown_syscall", "unimplemented_syscall", "syscall_exception", "instruction_limit", "normal_exit", "signal_termination", "unhandled_memory_violation", "explicit_stop", "backend_error", "breakpoint", or "watchpoint".
• app.last_stop_reason_code is the integer enum value for integrations that prefer stable numeric storage.
• app.last_stop_detail contains reason-specific detail, for example address=0x... size=... for an unhandled memory violation or count=... for an instruction limit.

Linux signal callbacks use app.callbacks.on_signal(signum, fault_addr, si_code). The callback fires at the start of native signal delivery, before the emulated process's handler or Linux's default termination path runs. It is observational: return values are ignored and cannot suppress guest delivery. on_exception is a Linux alias for the exact same callback slot and receives the same (signum, fault_addr, si_code) payload because Linux exceptions surface as signals. This alias is also shown by repr(app.callbacks) for runtime discoverability.

Linux memory violation callbacks use callback(address: int, size: int, operation: sogen.MemoryOperation, type: sogen.MemoryViolationType) -> sogen.MemoryViolationContinuation | bool | None. sogen.MemoryOperation is an alias of sogen.MemoryPermission, matching the backend operation values. None, True, and sogen.MemoryViolationContinuation.resume resume execution; False and sogen.MemoryViolationContinuation.stop stop with last_stop_reason == "unhandled_memory_violation"; and sogen.MemoryViolationContinuation.restart asks the backend to retry the faulting instruction. If no Linux memory violation callback or hook is installed, the emulator keeps its native SIGSEGV/default-stop path.

Linux low-level hooks

Linux emulators expose low-level hooks through app.hooks. Most methods are backend hooks; memory_violation(callback) is a Linux-managed observer that coexists with the emulator's internal SIGSEGV delivery path. Hook methods return sogen.linux.Hook handles with a read-only active property and an idempotent remove() method. Returned handles also stay active if you do not store them: app.hooks owns the hook until it is removed or the emulator is destroyed.

import sogen

emu = sogen.linux.create_empty(emulation_root="/")
emu.memory.allocate_memory_at(0x100000, 0x1000, sogen.MemoryPermission.exec)
emu.write_memory(0x100000, b"\x0f\xa2")  # cpuid
emu.write_register(sogen.Register.rip, 0x100000)


def on_cpuid(data):
    emu.stop()
    return sogen.HookContinuation.skip


hook = emu.hooks.instruction(sogen.Instruction.cpuid, on_cpuid)
emu.start(10)
hook.remove()

Available Linux hook methods are:

• app.hooks.memory_execution(callback)
• app.hooks.memory_execution_at(address, callback)
• app.hooks.memory_read(address, size, callback)
• app.hooks.memory_write(address, size, callback)
• app.hooks.instruction(sogen.Instruction.<name>, callback)
• app.hooks.interrupt(callback)
• app.hooks.memory_violation(callback)
• app.hooks.basic_block(callback)

Linux Hooks exposes Linux symbol hooks as app.hooks.symbols. Windows-only hooks.apis remains absent under sogen.linux.

Linux modules and symbol hooks

Linux applications expose initial ELF modules before app.start() and append runtime-loaded ELF modules as the dynamic loader maps them:

import ctypes
import sogen

app = sogen.linux.create_application("/bin/true", emulation_root="/")
for module in app.modules:
    print(module.name, hex(module.image_base), module.path)

Each sogen.linux.LinuxMappedModule has name, path, image_base, size_of_image, entry_point, exports, needed_libraries, sections, rpath, and runpath. Exports are sogen.linux.ExportedSymbol objects with name, rva, and address; sections are sogen.linux.MappedSection objects with name, start, length, and permissions. Executable ELF sections and regions expose composite permissions such as sogen.MemoryPermission.read_exec; write-execute mappings use sogen.MemoryPermission.write_exec. Use app.find_module_by_address(address) or app.find_module_by_name(name) to look up one module.

Symbol hooks are registered with app.hooks.symbols["symbol"] = callback or app.hooks.symbols["module!symbol"] = callback. The qualified form matches the Linux module name or filename stem case-sensitively. Assign None to a key to delete that hook, or call app.hooks.symbols.clear() to remove all symbol hooks.

Use @sogen.linux.symbol_call(params=[...], restype=...) to describe an x86_64 System V integer/pointer signature. Supported ctypes are integer and pointer-sized scalar/pointer ctypes up to 8 bytes; unsupported ctypes fail when the hook is registered. Parameters are decoded from rdi, rsi, rdx, rcx, r8, r9, then stack slots after the return address.

@sogen.linux.symbol_call(params=[ctypes.c_int], restype=ctypes.c_int)
def on_target(call, params):
    print(call.module.name, call.name, params[0])
    return sogen.ApiContinuation.run_original


app.hooks.symbols["target_function"] = on_target

Callbacks receive sogen.linux.LinuxSymbolCall with read-only module, name, address, and return_address, plus read-write return_value. Returning None, False, or sogen.ApiContinuation.run_original continues the original symbol. Returning True or sogen.ApiContinuation.intercept skips the original symbol by writing return_value to rax, setting rip to the saved return address, and advancing rsp by 8.

Backend support differs by engine. Unicorn and Icicle support fine-grained execution, read/write, instruction, interrupt, basic-block, and symbol hooks. KVM registers these hooks for API compatibility, but read/write, execution, basic-block, and symbol callbacks may not fire on that backend.

Linux debugger facade

Linux emulators expose app.debug, a Python-native debugger facade over the same backend hooks and CPU state used by low-level Linux hooks. Breakpoints are execute hooks: app.debug.set_breakpoint(address) arms one, clear_breakpoint(address) removes it, and list_breakpoints() returns the currently armed addresses. When execution reaches a breakpoint, app.last_stop_reason == "breakpoint", app.last_stop_detail includes the address, and app.debug.registers()["rip"] is the breakpoint address.

emu = sogen.linux.create_empty(emulation_root="/")
emu.memory.allocate_memory_at(0x100000, 0x1000, sogen.MemoryPermission.exec)
emu.write_memory(0x100000, b"\x0f\xa2\x0f\xa2")  # cpuid; cpuid
emu.write_register(sogen.Register.rip, 0x100000)
emu.debug.set_breakpoint(0x100002)
emu.debug.continue_execution()
assert emu.last_stop_reason == "breakpoint"

Stepping and run control methods are step_into(), step_over() (currently the same single-instruction primitive), run_to(address), continue_execution(), and pause(). step_out() uses a frame-pointer walk and raises diagnostic RuntimeErrors that distinguish zero RBP, an unreadable saved-return-address slot, and a zero saved return address. The messages suggest run_to(address) when an explicit destination is more reliable. Introspection methods return Python-native data: registers() returns a register dictionary; modules() and threads() return lists of dictionaries; disassemble(address, count_or_size) returns instruction dictionaries with address, bytes, mnemonic, operands, and size; and call_stack() returns a bounded best-effort frame-pointer walk.

API hooks

API hooks are registered through app.hooks.apis.

Use @sogen.windows.api_call(...) to describe calling convention and parameters. Top-level sogen.api_call(...) remains as compatibility alias.

Observe API call, then run original

import ctypes
import sogen

app = sogen.windows.create_application(
    "c:/test-sample.exe",
    emulation_root="./root",
)


@sogen.windows.api_call(cc=sogen.CallingConvention.stdcall, params=[ctypes.c_uint32])
def on_sleep(call, params):
    print(f"Sleep({params[0]})")


app.hooks.apis["Sleep"] = on_sleep
app.start()

Intercept API call and return custom value

import sogen

app = sogen.windows.create_application(
    "c:/hook-sample.exe",
    emulation_root="./root",
)


@sogen.windows.api_call(cc=sogen.CallingConvention.stdcall, params=[])
def on_get_current_process_id(call, params):
    call.return_value = 0xC0FFEE01
    return sogen.ApiContinuation.intercept


app.hooks.apis["GetCurrentProcessId"] = on_get_current_process_id
app.start()
print(app.process.exit_status)

Hook keys can be either:

• bare API name, for example "Sleep"
• qualified module form, for example "kernel32!Sleep"

Memory and state

The emulator exposes direct state access. Windows and Linux emulators both provide serialize_state() / deserialize_state(bytes) for explicit byte checkpoints and save_snapshot() / restore_snapshot() for an in-object snapshot slot.

import sogen

emu = sogen.linux.create_empty(emulation_root="/")
base = emu.memory.allocate_memory(0x1000, sogen.MemoryPermission.read_write)
emu.write_memory(base, b"ABCD")
emu.write_register(sogen.Register.rax, 0x1234)

state = emu.serialize_state()
emu.write_memory(base, b"WXYZ")
emu.write_register(sogen.Register.rax, 0)
emu.deserialize_state(state)
assert emu.read_memory(base, 4) == b"ABCD"
assert emu.read_register(sogen.Register.rax) == 0x1234

Linux serialized state uses version tag linux-emulator-state-v1 and includes backend CPU state, executed instruction count, stop diagnostics, mapped memory bytes and permissions, process ids, brk, argv/envp/auxv, threads, directory and epoll caches, ELF module metadata, signal actions, and mutable vDSO metadata. Open Linux file descriptors are serialized only for stdio, procfs/memory files, eventfds, directory descriptors, epoll descriptors, and host files that can be reopened by path and restored to their file offset. Live pipes, sockets, unnamed host descriptors, and unreopenable host descriptors raise during serialization or restore rather than being silently dropped.

Linux memory managers expose mapped-region introspection through app.memory.mapped_regions, app.memory.get_mapped_regions(), app.memory.get_region_info(address), and app.memory.compute_memory_stats(). mapped_regions returns sogen.linux.MemoryRegionInfo objects with start, length, permissions, allocation_base, allocation_length, is_reserved, is_committed, initial_permissions, and kind. Composite region permissions include sogen.MemoryPermission.read_exec and sogen.MemoryPermission.write_exec. Linux does not have the Windows reserve/commit split. Each mapped region reports:

• allocation_base == start
• allocation_length == length
• is_reserved is False
• is_committed is True
• initial_permissions == permissions
• kind == sogen.MemoryRegionKind.private_allocation

compute_memory_stats() returns a dictionary with:

• region_count
• mapped_bytes
• executable_bytes

Linux memory lifecycle callbacks observe successful native memory operations:

• app.callbacks.on_memory_allocate(address, length, permissions, committed) fires after mmap/allocation succeeds. Linux always passes committed=True because there is no reserve-only state.
• app.callbacks.on_memory_protect(address, length, permissions) fires after a protection change succeeds.
• app.callbacks.on_memory_release(address, length) fires after unmap/release succeeds.

For checkpoint-style workflows, use snapshots:

emu.save_snapshot()
# ... mutate state ...
emu.restore_snapshot()

Examples

Small runnable examples:

• examples/python/basic_usage.py for Windows
• examples/python/linux_true.py for Linux

Example setup notes:

• examples/python/README.md

Current limitations / expectations

• Windows bindings require an emulation root
• Windows samples in this repo assume Windows-style guest paths like c:/...
• Windows workflows are easiest to validate against repo sample binaries such as test-sample.exe and hook-sample.exe
• backend availability depends on platform and how Sogen was built