class Win32Emulator(WindowsEmulator):
"""
User Mode Windows Emulator Class
"""
def __init__(self, config, argv=[], debug=False, logger=None, exit_event=None):
super(Win32Emulator, self).__init__(
config, debug=debug, logger=logger, exit_event=exit_event
)
self.last_error = 0
self.peb_addr = 0
self.heap_allocs = []
self.argv = argv
self.sessman = SessionManager(config)
self.com = COM(config)
def get_argv(self):
"""
Get command line arguments (if any) that are being passed
to the emulated process. (e.g. main(argv))
"""
argv0 = ""
out = []
if len(self.argv):
for m in self.modules:
pe = m[0]
emu_path = m[2]
if pe.is_exe():
argv0 = emu_path
out = [argv0] + self.argv
elif self.command_line:
out = shlex.split(self.command_line, posix=False)
return out
def set_last_error(self, code):
"""
Set the last error code for the current thread
"""
if self.curr_thread:
self.curr_thread.set_last_error(code)
def get_last_error(self):
"""
Get the last error code for the current thread
"""
if self.curr_thread:
return self.curr_thread.get_last_error()
def get_session_manager(self):
"""
Get the session manager for the emulator. This will manage things like desktops,
windows, and session isolation
"""
return self.sessman
def add_vectored_exception_handler(self, first, handler):
"""
Add a vectored exception handler that will be executed on an exception
"""
self.veh_handlers.append(handler)
def remove_vectored_exception_handler(self, handler):
"""
Remove a vectored exception handler
"""
self.veh_handlers.remove(handler)
def get_processes(self):
if len(self.processes) <= 1:
self.init_processes(self.config_processes)
return self.processes
def init_processes(self, processes):
"""
Initialize configured processes set in the emulator config
"""
for proc in processes:
p = objman.Process(self)
self.add_object(p)
p.name = proc.get("name", "")
new_pid = proc.get("pid")
if new_pid:
p.pid = new_pid
base = proc.get("base_addr")
if isinstance(base, str):
base = int(base, 16)
p.base = base
p.path = proc.get("path")
p.session = proc.get("session", 0)
p.image = ntpath.basename(p.path)
self.processes.append(p)
def load_module(self, path=None, data=None, first_time_setup=True):
"""
Load a module into the emulator space from the specified path
"""
self._init_name(path, data)
pe = self.load_pe(path=path, data=data, imp_id=w32common.IMPORT_HOOK_ADDR)
if pe.arch == _arch.ARCH_X86:
disasm_mode = cs.CS_MODE_32
elif pe.arch == _arch.ARCH_AMD64:
disasm_mode = cs.CS_MODE_64
else:
raise Win32EmuError("Unsupported architecture: %s", pe.arch)
if not self.arch:
self.arch = pe.arch
self.set_ptr_size(self.arch)
# No need to initialize the engine and Capstone again
if first_time_setup:
self.emu_eng.init_engine(_arch.ARCH_X86, pe.arch)
if not self.disasm_eng:
self.disasm_eng = cs.Cs(cs.CS_ARCH_X86, disasm_mode)
self.api = WindowsApi(self)
cd = self.get_cd()
if not cd.endswith("\\"):
cd += "\\"
emu_path = cd + self.file_name
if not data:
with open(path, "rb") as f:
data = f.read()
self.fileman.add_existing_file(emu_path, data)
# Strings the initial buffer so that we can detect decoded strings later on
if self.profiler and self.do_strings:
self.profiler.strings["ansi"] = [a[1] for a in self.get_ansi_strings(data)]
self.profiler.strings["unicode"] = [
u[1] for u in self.get_unicode_strings(data)
]
# Set the emulated path
emu_path = ""
self.cd = self.get_cd()
if self.cd:
if not self.cd.endswith('\\'):
self.cd += '\\'
emu_path = self.cd + os.path.basename(self.file_name)
pe.set_emu_path(emu_path)
# There's a bit of a problem here, if we cannot reserve memory
# at the PE's desired base address, and the relocation table
# is not present, we can't rebase it. So this is gonna have to
# be a bit of a hack for binaries without a relocation table.
# This logic is really only for child processes, since we're pretty
# much guarenteed memory at the base address of the main module.
# 1. If the memory at the child's desired load address is already
# being used, remap it somewhere else. I'm pretty sure that
# the already-used memory will always be for a module,
# since desired load addresses don't really vary across PEs
# 2. Fix up any modules that speakeasy has open for the parent
# to reflect where it was remapped
# 3. Try and grab memory at the child's desired base address,
# if that isn't still isn't possible, we're out of luck
#
# But if the relocation table is present, we can rebase it,
# so we do that instead of the above hack.
imgbase = pe.OPTIONAL_HEADER.ImageBase
ranges = self.get_valid_ranges(pe.image_size, addr=imgbase)
base, size = ranges
if base != imgbase:
if pe.has_reloc_table():
pe.rebase(base)
else:
parent_map = self.get_address_map(imgbase)
# Already being used by the parent, so let's remap the parent
# Do get_valid_ranges on the parent map size so we get a
# suitable region for it
new_parent_mem, unused = self.get_valid_ranges(parent_map.size)
new_parent_mem = self.mem_remap(imgbase, new_parent_mem)
# Failed
if new_parent_mem == -1:
# XXX what to do here
pass
# Update parent module pointer
for pe_, ranges_, emu_path_ in self.modules:
base_, size_ = ranges_
if base_ == imgbase:
self.modules.remove((pe_, ranges_, emu_path_))
self.modules.append((pe_, (new_parent_mem, size_), emu_path_))
break
# Alright, let's try to grab that memory for the child again
ranges = self.get_valid_ranges(pe.image_size, addr=imgbase)
base, size = ranges
if base != imgbase:
# Out of luck
# XXX what to do here
pass
self.mem_map(pe.image_size, base=base,
tag='emu.module.%s' % (self.mod_name))
self.modules.append((pe, ranges, emu_path))
self.mem_write(pe.base, pe.mapped_image)
self.setup(first_time_setup=first_time_setup)
if not self.stack_base:
self.stack_base, stack_addr = self.alloc_stack(0x12000)
self.set_func_args(self.stack_base, self.return_hook)
# Init imported data
for addr, imp in pe.imports.items():
mn, fn = imp
mod, eh = self.api.get_data_export_handler(mn, fn)
if eh:
data_ptr = self.handle_import_data(mn, fn)
sym = "%s.%s" % (mn, fn)
self.global_data.update({addr: [sym, data_ptr]})
self.mem_write(addr, data_ptr.to_bytes(self.get_ptr_size(), "little"))
return pe
def prepare_module_for_emulation(self, module, all_entrypoints, entrypoints):
if not module:
self.stop()
raise Win32EmuError("Module not found")
# Check if any TLS callbacks exist, these run before the module's entry point
tls = module.get_tls_callbacks()
for i, cb_addr in enumerate(tls):
base = module.get_base()
if base < cb_addr < base + module.get_image_size():
run = Run()
run.start_addr = cb_addr
run.type = "tls_callback_%d" % (i)
run.args = [base, DLL_PROCESS_ATTACH, 0]
self.add_run(run)
ep = module.base + module.ep
run = Run()
run.start_addr = ep
main_exe = None
if not module.is_exe():
run.args = [module.base, DLL_PROCESS_ATTACH, 0]
run.type = "dll_entry.DLL_PROCESS_ATTACH"
container = self.init_container_process()
if container:
self.processes.append(container)
self.curr_process = container
else:
run.type = "module_entry"
main_exe = module
run.args = [
self.mem_map(8, tag="emu.module_arg_%d" % (i)) for i in range(4)
]
if main_exe:
self.user_modules = [main_exe] + self.user_modules
# we consider this run only if all entry_points is selected or DLL_PROCESS_ATTACH is in the entrypoints
if all_entrypoints or "DLL_PROCESS_ATTACH" in entrypoints:
self.add_run(run)
if all_entrypoints or entrypoints:
# Only emulate a subset of all the exported functions
# There are some modules (such as the windows kernel) with
# thousands of exports
exports = [k for k in module.get_exports()[:MAX_EXPORTS_TO_EMULATE]]
if exports:
args = [
self.mem_map(8, tag="emu.export_arg_%d" % (i), base=0x41420000)
for i in range(4)
] # noqa
for exp in exports:
if exp.name in ("DllMain",):
continue
if all_entrypoints or exp.name in entrypoints:
run = Run()
if exp.name:
fn = exp.name
else:
fn = "no_name"
run.type = "export.%s" % (fn)
run.start_addr = exp.address
if exp.name == "ServiceMain":
# ServiceMain accepts a (argc, argv) pair like main().
#
# now, we're not exactly sure if we're in A or W mode.
# maybe there are some hints we could take to guess this.
# instead, we'll assume W mode and use default service name "IPRIP".
#
# hack: if we're actually in A mode, then string routines
# will think the service name is "I" which isn't perfect,
# but might still be good enough.
#
# layout:
# argc: 1
# argv:
# 0x00: (argv[0]) pointer to +0x10 -+
# 0x04/08: (argv[1]) 0x0 |
# 0x10: "IPRIP" <------------------+
svc_name = "IPRIP\x00".encode("utf-16le")
argc = 1
argv = self.mem_map(
len(svc_name) + 0x10,
tag="emu.export_ServiceMain_argv",
base=0x41420000,
)
self.write_ptr(argv, argv + 0x10)
self.mem_write(argv + 0x10, svc_name)
run.args = [argc, argv]
else:
# Here we set dummy args to pass into the export function
run.args = args
# Store these runs and only queue them before the unload
# routine this is because some exports may not be ready to
# be called yet
self.add_run(run)
return
def run_module(self, module, all_entrypoints=False, emulate_children=False, entrypoints=None):
"""
Begin emulating a previously loaded module
Arguments:
module: Module to emulate
"""
if entrypoints is None:
entrypoints = []
self.prepare_module_for_emulation(module, all_entrypoints, entrypoints)
# Create an empty process object for the module if none is
# supplied, only do this for the main module
if len(self.processes) == 0:
p = objman.Process(
self,
path=module.get_emu_path(),
base=module.base,
pe=module,
cmdline=self.command_line,
)
self.curr_process = p
self.om.objects.update({p.address: p})
mm = self.get_address_map(module.base)
if mm:
mm.process = self.curr_process
t = objman.Thread(
self, stack_base=self.stack_base, stack_commit=module.stack_commit
)
self.om.objects.update({t.address: t})
self.curr_process.threads.append(t)
self.curr_thread = t
peb = self.alloc_peb(self.curr_process)
# Set the TEB
self.init_teb(t, peb)
# Begin emulation of main module
self.start()
if not emulate_children or len(self.child_processes) == 0:
return
# Emulate any child processes
while len(self.child_processes) > 0:
child = self.child_processes.pop(0)
child.pe = self.load_module(data=child.pe_data, first_time_setup=False)
self.prepare_module_for_emulation(child.pe, all_entrypoints, entrypoints)
self.command_line = child.cmdline
self.curr_process = child
self.curr_process.base = child.pe.base
self.curr_thread = child.threads[0]
self.om.objects.update({self.curr_thread.address: self.curr_thread})
# PEB and TEB will be initialized when the next run happens
self.start()
return
def _init_name(self, path, data=None):
if not data:
self.file_name = os.path.basename(path)
self.mod_name = os.path.splitext(self.file_name)[0]
else:
mod_hash = hashlib.sha256()
mod_hash.update(data)
mod_hash = mod_hash.hexdigest()
self.mod_name = mod_hash
self.file_name = f"{self.mod_name}.exe"
self.bin_base_name = os.path.basename(self.file_name)
def emulate_module(self, path):
"""
Load and emulate binary from the given path
"""
mod = self.load_module(path)
self.run_module(mod)
def load_shellcode(self, path, arch, data=None):
"""
Load position independent code (i.e. shellcode) to prepare for emulation
"""
sc_hash = None
self._init_name(path, data)
if arch == "x86":
arch = _arch.ARCH_X86
elif arch in ("x64", "amd64"):
arch = _arch.ARCH_AMD64
self.arch = arch
if data:
sc_hash = hashlib.sha256()
sc_hash.update(data)
sc_hash = sc_hash.hexdigest()
sc = data
else:
with open(path, "rb") as scpath:
sc = scpath.read()
sc_hash = hashlib.sha256()
sc_hash.update(sc)
sc_hash = sc_hash.hexdigest()
if self.arch == _arch.ARCH_X86:
disasm_mode = cs.CS_MODE_32
elif self.arch == _arch.ARCH_AMD64:
disasm_mode = cs.CS_MODE_64
else:
raise Win32EmuError("Unsupported architecture: %s" % self.arch)
self.emu_eng.init_engine(_arch.ARCH_X86, self.arch)
if not self.disasm_eng:
self.disasm_eng = cs.Cs(cs.CS_ARCH_X86, disasm_mode)
sc_tag = "emu.shellcode.%s" % (sc_hash)
# Map the shellcode into memory
sc_addr = self.mem_map(len(sc), tag=sc_tag)
self.mem_write(sc_addr, sc)
self.pic_buffers.append((path, sc_addr, len(sc)))
sc_arch = "unknown"
if arch == _arch.ARCH_AMD64:
sc_arch = "x64"
elif arch == _arch.ARCH_X86:
sc_arch = "x86"
if self.profiler:
self.input = {
"path": path,
"sha256": sc_hash,
"size": len(sc),
"arch": sc_arch,
"mem_tag": sc_tag,
"emu_version": self.get_emu_version(),
"os_run": self.get_osver_string(),
}
self.profiler.add_input_metadata(self.input)
# Strings the initial buffer so that we can detect decoded strings later on
if self.do_strings:
self.profiler.strings["ansi"] = [
a[1] for a in self.get_ansi_strings(sc)
]
self.profiler.strings["unicode"] = [
u[1] for u in self.get_unicode_strings(sc)
]
self.setup()
return sc_addr
def run_shellcode(self, sc_addr, offset=0):
"""
Begin emulating position independent code (i.e. shellcode) to prepare for emulation
"""
target = None
for sc_path, _sc_addr, size in self.pic_buffers:
if _sc_addr == sc_addr:
target = _sc_addr
break
if not target:
raise Win32EmuError("Invalid shellcode address")
stack_commit = 0x4000
self.stack_base, stack_addr = self.alloc_stack(stack_commit)
self.set_func_args(self.stack_base, self.return_hook, 0x7000)
run = Run()
run.type = "shellcode"
run.start_addr = sc_addr + offset
run.instr_cnt = 0
args = [
self.mem_map(1024, tag="emu.shellcode_arg_%d" % (i), base=0x41420000 + i)
for i in range(4)
]
run.args = args
self.reg_write(_arch.X86_REG_ECX, 1024)
self.add_run(run)
# Create an empty process object for the shellcode if none is
# supplied
container = self.init_container_process()
if container:
self.processes.append(container)
self.curr_process = container
else:
p = objman.Process(self)
self.processes.append(p)
self.curr_process = p
mm = self.get_address_map(sc_addr)
if mm:
mm.set_process(self.curr_process)
t = objman.Thread(self, stack_base=self.stack_base, stack_commit=stack_commit)
self.om.objects.update({t.address: t})
self.curr_process.threads.append(t)
self.curr_thread = t
peb = self.alloc_peb(self.curr_process)
# Set the TEB
self.init_teb(t, peb)
self.start()
def alloc_peb(self, proc):
"""
Allocate memory for the Process Environment Block (PEB)
"""
if proc.is_peb_active:
return
size = proc.get_peb_ldr().sizeof()
res, size = self.get_valid_ranges(size)
self.mem_reserve(size, base=res, tag="emu.struct.PEB_LDR_DATA")
proc.set_peb_ldr_address(res)
peb = proc.get_peb()
proc.is_peb_active = True
peb.object.ImageBaseAddress = proc.base
peb.object.OSMajorVersion = self.osversion["major"]
peb.object.OSMinorVersion = self.osversion["minor"]
peb.object.OSBuildNumber = self.osversion["build"]
peb.write_back()
return peb
def set_unhandled_exception_handler(self, handler_addr):
"""
Establish a handler for unhandled exceptions that occur during emulation
"""
self.unhandled_exception_filter = handler_addr
def setup(self, stack_commit=0, first_time_setup=True):
if first_time_setup:
# Set the emulator to run in protected mode
self.om = objman.ObjectManager(emu=self)
arch = self.get_arch()
self._setup_gdt(arch)
self.setup_user_shared_data()
self.set_ptr_size(self.arch)
if arch == _arch.ARCH_X86:
self.peb_addr = self.fs_addr + 0x30
elif arch == _arch.ARCH_AMD64:
self.peb_addr = self.gs_addr + 0x60
self.api = WindowsApi(self)
# Init symlinks
for sl in self.symlinks:
self.om.add_symlink(sl["name"], sl["target"])
self.init_sys_modules(self.config_system_modules)
def init_sys_modules(self, modules_config):
"""
Get the system modules (e.g. drivers) that are loaded in the emulator
"""
sys_mods = []
for modconf in modules_config:
mod = w32common.DecoyModule()
mod.name = modconf["name"]
base = modconf.get("base_addr")
if isinstance(base, str):
base = int(base, 16)
mod.decoy_base = base
mod.decoy_path = modconf["path"]
drv = modconf.get("driver")
if drv:
devs = drv.get("devices")
for dev in devs:
name = dev.get("name", "")
do = self.new_object(objman.Device)
do.name = name
sys_mods.append(mod)
return sys_mods
def init_container_process(self):
"""
Create a process to be used to host shellcode or DLLs
"""
for p in self.config_processes:
if p.get("is_main_exe"):
name = p.get("name", "")
emu_path = p.get("path", "")
base = p.get("base_addr", 0)
if isinstance(base, str):
base = int(base, 0)
cmd_line = p.get("command_line", "")
proc = objman.Process(
self, name=name, path=emu_path, base=base, cmdline=cmd_line
)
return proc
return None
def get_user_modules(self):
"""
Get the user modules (e.g. dlls) that are loaded in the emulator
"""
# Generate the decoy user module list
if len(self.user_modules) < 2:
# Check if we have a host process configured
proc_mod = None
for p in self.config_processes:
if not self.user_modules and p.get("is_main_exe"):
proc_mod = p
break
if proc_mod:
all_user_mods = [proc_mod] + self.config_user_modules
user_modules = self.init_user_modules(all_user_mods)
else:
user_modules = self.init_user_modules(self.config_user_modules)
self.user_modules += user_modules
# add sample to user modules list if it is a dll
if self.modules and not self.modules[0][0].is_exe():
self.user_modules.append(self.modules[0][0])
return self.user_modules
def exit_process(self):
"""
An emulated binary is attempted to terminate its current process.
Signal that the run has finished.
"""
self.enable_code_hook()
self.run_complete = True
def _hook_mem_unmapped(self, emu, access, address, size, value, user_data):
_access = self.emu_eng.mem_access.get(access)
if _access == common.INVALID_MEM_READ:
p = self.get_current_process()
pld = p.get_peb_ldr()
if address > pld.address and address < (pld.address + pld.sizeof()):
self.mem_map_reserve(pld.address)
user_mods = self.get_user_modules()
self.init_peb(user_mods)
return True
return super(Win32Emulator, self)._hook_mem_unmapped(
emu, access, address, size, value, user_data
)
def set_hooks(self):
"""Set the emulator callbacks"""
super(Win32Emulator, self).set_hooks()
if not self.builtin_hooks_set:
self.add_mem_invalid_hook(cb=self._hook_mem_unmapped)
self.add_interrupt_hook(cb=self._hook_interrupt)
self.builtin_hooks_set = True
self.set_mem_tracing_hooks()
def stop(self):
self.run_complete = True
# self._unset_emu_hooks()
# self.unset_hooks()
super(Win32Emulator, self).stop()
def on_emu_complete(self):
"""
Called when all runs have completed emulation
"""
if not self.emu_complete:
self.emu_complete = True
if self.do_strings and self.profiler:
dec_ansi, dec_unicode = self.get_mem_strings()
dec_ansi = [
a[1] for a in dec_ansi if a not in self.profiler.strings["ansi"]
]
dec_unicode = [
u[1]
for u in dec_unicode
if u not in self.profiler.strings["unicode"]
]
self.profiler.decoded_strings["ansi"] = dec_ansi
self.profiler.decoded_strings["unicode"] = dec_unicode
self.stop()
def on_run_complete(self):
"""
Clean up after a run completes. This function will pop the
next run from the run queue and emulate it.
"""
self.run_complete = True
self.curr_run.ret_val = self.get_return_val()
if self.profiler:
self.profiler.log_dropped_files(self.curr_run, self.get_dropped_files())
return self._exec_next_run()
def heap_alloc(self, size, heap="None"):
"""
Allocate a memory chunk and add it to the "heap"
"""
addr = self.mem_map(size, base=None, tag="api.heap.%s" % (heap))
self.heap_allocs.append((addr, size, heap))
return addr
class Win32Emulator(WindowsEmulator):
"""
User Mode Windows Emulator Class
"""
def __init__(self,
config,
argv=[],
debug=False,
logger=None,
exit_event=None):
super(Win32Emulator, self).__init__(config,
debug=debug,
logger=logger,
exit_event=exit_event)
self.last_error = 0
self.peb_addr = 0
self.heap_allocs = []
self.argv = argv
self.sessman = SessionManager(config)
self.com = COM(config)
def get_argv(self):
"""
Get command line arguments (if any) that are being passed
to the emulated process. (e.g. main(argv))
"""
argv0 = ''
out = []
if len(self.argv):
for m in self.modules:
pe = m[0]
emu_path = m[2]
if pe.is_exe():
argv0 = emu_path
out = [argv0] + self.argv
elif self.command_line:
out = shlex.split(self.command_line, posix=False)
return out
def set_last_error(self, code):
"""
Set the last error code for the current thread
"""
if self.curr_thread:
self.curr_thread.set_last_error(code)
def get_last_error(self):
"""
Get the last error code for the current thread
"""
if self.curr_thread:
return self.curr_thread.get_last_error()
def get_session_manager(self):
"""
Get the session manager for the emulator. This will manage things like desktops,
windows, and session isolation
"""
return self.sessman
def add_vectored_exception_handler(self, first, handler):
"""
Add a vectored exception handler that will be executed on an exception
"""
self.veh_handlers.append(handler)
def remove_vectored_exception_handler(self, handler):
"""
Remove a vectored exception handler
"""
self.veh_handlers.remove(handler)
def get_processes(self):
if len(self.processes) <= 1:
self.init_processes(self.config_processes)
return self.processes
def init_processes(self, processes):
"""
Initialize configured processes set in the emulator config
"""
for proc in processes:
p = objman.Process(self)
self.add_object(p)
p.name = proc.get('name', '')
new_pid = proc.get('pid')
if new_pid:
p.pid = new_pid
base = proc.get('base_addr')
if isinstance(base, str):
base = int(base, 16)
p.base = base
p.path = proc.get('path')
p.session = proc.get('session', 0)
p.image = ntpath.basename(p.path)
self.processes.append(p)
def load_module(self, path=None, data=None):
"""
Load a module into the emulator space from the specified path
"""
pe = self.load_pe(path=path,
data=data,
imp_id=w32common.IMPORT_HOOK_ADDR)
if pe.arch == _arch.ARCH_X86:
disasm_mode = cs.CS_MODE_32
elif pe.arch == _arch.ARCH_AMD64:
disasm_mode = cs.CS_MODE_64
else:
raise Win32EmuError('Unsupported architecture: %s', pe.arch)
if not self.arch:
self.arch = pe.arch
self.set_ptr_size(self.arch)
self.emu_eng.init_engine(_arch.ARCH_X86, pe.arch)
if not self.disasm_eng:
self.disasm_eng = cs.Cs(cs.CS_ARCH_X86, disasm_mode)
if not data:
file_name = os.path.basename(path) + '.exe'
mod_name = os.path.splitext(file_name)[0]
else:
mod_hash = hashlib.sha256()
mod_hash.update(data)
mod_hash = mod_hash.hexdigest()
mod_name = mod_hash
file_name = '%s.exe' % (mod_name)
self.api = WindowsApi(self)
cd = self.get_cd()
if not cd.endswith('\\'):
cd += '\\'
emu_path = cd + file_name
if not data:
with open(path, 'rb') as f:
data = f.read()
self.fileman.add_existing_file(emu_path, data)
# Strings the initial buffer so that we can detect decoded strings later on
if self.profiler and self.do_strings:
self.profiler.strings['ansi'] = self.get_ansi_strings(data)
self.profiler.strings['unicode'] = self.get_unicode_strings(data)
# Set the emulated path
emu_path = ''
self.cd = self.get_cd()
if self.cd:
if not self.cd.endswith('\\'):
self.cd += '\\'
emu_path = self.cd + os.path.basename(file_name)
pe.set_emu_path(emu_path)
self.map_pe(pe, mod_name=mod_name, emu_path=emu_path)
self.mem_write(pe.base, pe.mapped_image)
self.setup()
if not self.stack_base:
self.stack_base, stack_addr = self.alloc_stack(0x12000)
self.set_func_args(self.stack_base, self.return_hook)
# Init imported data
for addr, imp in pe.imports.items():
mn, fn = imp
mod, eh = self.api.get_data_export_handler(mn, fn)
if eh:
data_ptr = self.handle_import_data(mn, fn)
sym = "%s.%s" % (mn, fn)
self.global_data.update({addr: [sym, data_ptr]})
self.mem_write(
addr, data_ptr.to_bytes(self.get_ptr_size(), 'little'))
return pe
def run_module(self, module, all_entrypoints=False):
"""
Begin emulating a previously loaded module
Arguments:
module: Module to emulate
"""
if not module:
self.stop()
raise Win32EmuError('Module not found')
# Check if any TLS callbacks exist, these run before the module's entry point
tls = module.get_tls_callbacks()
for i, cb_addr in enumerate(tls):
base = module.get_base()
if base < cb_addr < base + module.get_image_size():
run = Run()
run.start_addr = cb_addr
run.type = 'tls_callback_%d' % (i)
run.args = [base, DLL_PROCESS_ATTACH, 0]
self.add_run(run)
# Queue up the module's main entry point
ep = module.base + module.ep
run = Run()
run.start_addr = ep
main_exe = None
if not module.is_exe():
run.args = [module.base, DLL_PROCESS_ATTACH, 0]
run.type = 'dll_entry.DLL_PROCESS_ATTACH'
container = self.init_container_process()
if container:
self.processes.append(container)
self.curr_process = container
else:
run.type = 'module_entry'
main_exe = module
run.args = [
self.mem_map(8, tag='emu.module_arg_%d' % (i))
for i in range(4)
]
if main_exe:
self.user_modules = [main_exe] + self.user_modules
self.add_run(run)
if all_entrypoints:
# Only emulate a subset of all the exported functions
# There are some modules (such as the windows kernel) with
# thousands of exports
exports = [
k for k in module.get_exports()[:MAX_EXPORTS_TO_EMULATE]
]
if exports:
args = [
self.mem_map(8,
tag='emu.export_arg_%d' % (i),
base=0x41420000) for i in range(4)
] # noqa
for exp in exports:
if exp.name in ('DllMain', 'ServiceMain'):
continue
run = Run()
if exp.name:
fn = exp.name
else:
fn = 'no_name'
run.type = 'export.%s' % (fn)
run.start_addr = exp.address
# Here we set dummy args to pass into the export function
run.args = args
# Store these runs and only queue them before the unload
# routine this is because some exports may not be ready to
# be called yet
self.add_run(run)
# Create an empty process object for the module if none is
# supplied
if len(self.processes) == 0:
p = objman.Process(self,
path=module.get_emu_path(),
base=module.base,
pe=module,
cmdline=self.command_line)
self.curr_process = p
self.om.objects.update({p.address: p})
mm = self.get_address_map(module.base)
if mm:
mm.process = self.curr_process
t = objman.Thread(self,
stack_base=self.stack_base,
stack_commit=module.stack_commit)
self.om.objects.update({t.address: t})
self.curr_process.threads.append(t)
self.curr_thread = t
peb = self.alloc_peb(self.curr_process)
# Set the TEB
self.init_teb(t, peb)
# Begin emulation
self.start()
def emulate_module(self, path):
"""
Load and emulate binary from the given path
"""
mod = self.load_module(path)
self.run_module(mod)
def load_shellcode(self, path, arch, data=None):
"""
Load position independent code (i.e. shellcode) to prepare for emulation
"""
sc_hash = None
if arch == 'x86':
arch = _arch.ARCH_X86
elif arch in ('x64', 'amd64'):
arch = _arch.ARCH_AMD64
self.arch = arch
if data:
sc_hash = hashlib.sha256()
sc_hash.update(data)
sc_hash = sc_hash.hexdigest()
sc = data
else:
with open(path, 'rb') as scpath:
sc = scpath.read()
sc_hash = hashlib.sha256()
sc_hash.update(sc)
sc_hash = sc_hash.hexdigest()
if self.arch == _arch.ARCH_X86:
disasm_mode = cs.CS_MODE_32
elif self.arch == _arch.ARCH_AMD64:
disasm_mode = cs.CS_MODE_64
else:
raise Win32EmuError('Unsupported architecture: %s' % self.arch)
self.emu_eng.init_engine(_arch.ARCH_X86, self.arch)
if not self.disasm_eng:
self.disasm_eng = cs.Cs(cs.CS_ARCH_X86, disasm_mode)
sc_tag = 'emu.shellcode.%s' % (sc_hash)
# Map the shellcode into memory
sc_addr = self.mem_map(len(sc), tag=sc_tag)
self.mem_write(sc_addr, sc)
self.pic_buffers.append((path, sc_addr, len(sc)))
sc_arch = 'unknown'
if arch == _arch.ARCH_AMD64:
sc_arch = 'x64'
elif arch == _arch.ARCH_X86:
sc_arch = 'x86'
if self.profiler:
self.input = {
'path': path,
'sha256': sc_hash,
'size': len(sc),
'arch': sc_arch,
'mem_tag': sc_tag,
'emu_version': self.get_emu_version(),
'os_run': self.get_osver_string()
}
self.profiler.add_input_metadata(self.input)
# Strings the initial buffer so that we can detect decoded strings later on
if self.do_strings:
self.profiler.strings['ansi'] = self.get_ansi_strings(sc)
self.profiler.strings['unicode'] = self.get_unicode_strings(sc)
self.setup()
return sc_addr
def run_shellcode(self, sc_addr, offset=0):
"""
Begin emulating position independent code (i.e. shellcode) to prepare for emulation
"""
target = None
for sc_path, _sc_addr, size in self.pic_buffers:
if _sc_addr == sc_addr:
target = _sc_addr
break
if not target:
raise Win32EmuError('Invalid shellcode address')
stack_commit = 0x4000
self.stack_base, stack_addr = self.alloc_stack(stack_commit)
self.set_func_args(self.stack_base, self.return_hook, 0x7000)
run = Run()
run.type = 'shellcode'
run.start_addr = sc_addr + offset
run.instr_cnt = 0
args = [
self.mem_map(1024,
tag='emu.shellcode_arg_%d' % (i),
base=0x41420000 + i) for i in range(4)
]
run.args = (args)
self.reg_write(_arch.X86_REG_ECX, 1024)
self.add_run(run)
# Create an empty process object for the shellcode if none is
# supplied
container = self.init_container_process()
if container:
self.processes.append(container)
self.curr_process = container
else:
p = objman.Process(self)
self.processes.append(p)
self.curr_process = p
mm = self.get_address_map(sc_addr)
if mm:
mm.set_process(self.curr_process)
t = objman.Thread(self,
stack_base=self.stack_base,
stack_commit=stack_commit)
self.om.objects.update({t.address: t})
self.curr_process.threads.append(t)
self.curr_thread = t
peb = self.alloc_peb(self.curr_process)
# Set the TEB
self.init_teb(t, peb)
self.start()
def alloc_peb(self, proc):
"""
Allocate memory for the Process Environment Block (PEB)
"""
if proc.is_peb_active:
return
size = proc.get_peb_ldr().sizeof()
res, size = self.get_valid_ranges(size)
self.mem_reserve(size, base=res, tag='emu.struct.PEB_LDR_DATA')
proc.set_peb_ldr_address(res)
peb = proc.get_peb()
proc.is_peb_active = True
peb.object.ImageBaseAddress = proc.base
peb.write_back()
return peb
def set_unhandled_exception_handler(self, handler_addr):
"""
Establish a handler for unhandled exceptions that occur during emulation
"""
self.unhandled_exception_filter = handler_addr
def setup(self, stack_commit=0):
# Set the emulator to run in protected mode
self.om = objman.ObjectManager(emu=self)
arch = self.get_arch()
self._setup_gdt(arch)
self.setup_user_shared_data()
self.set_ptr_size(self.arch)
if arch == _arch.ARCH_X86:
self.peb_addr = self.fs_addr + 0x30
elif arch == _arch.ARCH_AMD64:
self.peb_addr = self.gs_addr + 0x60
self.api = WindowsApi(self)
# Init symlinks
for sl in self.symlinks:
self.om.add_symlink(sl['name'], sl['target'])
self.init_sys_modules(self.config_system_modules)
def init_sys_modules(self, modules_config):
"""
Get the system modules (e.g. drivers) that are loaded in the emulator
"""
sys_mods = []
for modconf in modules_config:
mod = w32common.DecoyModule()
mod.name = modconf['name']
base = modconf.get('base_addr')
if isinstance(base, str):
base = int(base, 16)
mod.decoy_base = base
mod.decoy_path = modconf['path']
drv = modconf.get('driver')
if drv:
devs = drv.get('devices')
for dev in devs:
name = dev.get('name', '')
do = self.new_object(objman.Device)
do.name = name
sys_mods.append(mod)
return sys_mods
def init_container_process(self):
"""
Create a process to be used to host shellcode or DLLs
"""
for p in self.config_processes:
if p.get('is_main_exe'):
name = p.get('name', '')
emu_path = p.get('path', '')
base = p.get('base_addr', 0)
if isinstance(base, str):
base = int(base, 0)
cmd_line = p.get('command_line', '')
proc = objman.Process(self,
name=name,
path=emu_path,
base=base,
cmdline=cmd_line)
return proc
return None
def get_user_modules(self):
"""
Get the user modules (e.g. dlls) that are loaded in the emulator
"""
# Generate the decoy user module list
if len(self.user_modules) < 2:
# Check if we have a host process configured
proc_mod = None
for p in self.config_processes:
if not self.user_modules and p.get('is_main_exe'):
proc_mod = p
break
if proc_mod:
all_user_mods = [proc_mod] + self.config_user_modules
user_modules = self.init_user_modules(all_user_mods)
else:
user_modules = self.init_user_modules(self.config_user_modules)
self.user_modules += user_modules
# add sample to user modules list if it is a dll
if self.modules and not self.modules[0][0].is_exe():
self.user_modules.append(self.modules[0][0])
return self.user_modules
def exit_process(self):
"""
An emulated binary is attempted to terminate its current process.
Signal that the run has finished.
"""
self.enable_code_hook()
self.run_complete = True
def _hook_mem_unmapped(self, emu, access, address, size, value, user_data):
_access = self.emu_eng.mem_access.get(access)
if _access == common.INVALID_MEM_READ:
p = self.get_current_process()
pld = p.get_peb_ldr()
if address > pld.address and address < (pld.address +
pld.sizeof()):
self.mem_map_reserve(pld.address)
user_mods = self.get_user_modules()
self.init_peb(user_mods)
return True
return super(Win32Emulator,
self)._hook_mem_unmapped(emu, access, address, size,
value, user_data)
def set_hooks(self):
"""Set the emulator callbacks"""
super(Win32Emulator, self).set_hooks()
if not self.builtin_hooks_set:
self.add_mem_invalid_hook(cb=self._hook_mem_unmapped)
self.add_interrupt_hook(cb=self._hook_interrupt)
self.builtin_hooks_set = True
self.set_mem_tracing_hooks()
def stop(self):
self.run_complete = True
super(Win32Emulator, self).stop()
def on_emu_complete(self):
"""
Called when all runs have completed emulation
"""
if not self.emu_complete:
self.emu_complete = True
if self.do_strings and self.profiler:
dec_ansi, dec_unicode = self.get_mem_strings()
dec_ansi = [
a for a in dec_ansi
if a not in self.profiler.strings['ansi']
]
dec_unicode = [
u for u in dec_unicode
if u not in self.profiler.strings['unicode']
]
self.profiler.decoded_strings['ansi'] = dec_ansi
self.profiler.decoded_strings['unicode'] = dec_unicode
self.stop()
def on_run_complete(self):
"""
Clean up after a run completes. This function will pop the
next run from the run queue and emulate it.
"""
self.run_complete = True
self.curr_run.ret_val = self.get_return_val()
if self.profiler:
self.profiler.log_dropped_files(self.curr_run,
self.get_dropped_files())
return self._exec_next_run()
def heap_alloc(self, size, heap='None'):
"""
Allocate a memory chunk and add it to the "heap"
"""
addr = self.mem_map(size, base=None, tag='api.heap.%s' % (heap))
self.heap_allocs.append((addr, size, heap))
return addr
class WinKernelEmulator(WindowsEmulator, IoManager):
"""
Class used to emulate Windows drivers
"""
def __init__(self, config, debug=False, logger=None, exit_event=None):
super(WinKernelEmulator, self).__init__(config,
debug=debug,
logger=logger,
exit_event=exit_event)
self.disasm_eng = None
self.curr_mod = None
self.debug = debug
self.drivers = []
self.pool_allocs = []
self.all_entrypoints = False
self.kernel_mode = True
self.irql = ddk.PASSIVE_LEVEL
self.delayed_runs = []
self.system_time = SYSTEM_TIME_START
self.ktypes = ntos
def get_system_time(self):
return self.system_time
def get_system_process(self):
"""
Get the process object for the system process (PID 4)
"""
for proc in self.processes:
if proc.get_pid() == 4:
return proc
def get_current_irql(self):
"""
Get the current interrupt request level
"""
return self.irql
def set_current_irql(self, irql):
"""
Set the current interrupt request level
"""
self.irql = irql
def create_driver_object(self, name=None, pe=None):
"""
Create a driver object for the driver that is going to be emulated
"""
drv = objman.Driver(emu=self)
# If no PE was supplied, assign a dummy driver
if not pe:
# Get the path for the dummy driver
default_path = self.get_native_module_path('default_sys')
pe = w32common.DecoyModule(path=default_path)
if name:
bn = ntpath.basename(name)
else:
bn = 'none'
pe.decoy_path = ('%sdrivers\\%s.sys' %
(self.get_system_root(), os.path.basename(bn)))
pe.decoy_base = pe.get_base()
else:
if not name:
bn = pe.path
path = '%sdrivers\\%s' % (self.get_system_root(),
os.path.basename(bn))
pe.decoy_path = path
pe.decoy_base = pe.base
drv.init_driver_object(name, pe, is_decoy=False)
self.add_object(drv)
self.drivers.append(drv)
return drv
def load_module(self, path=None, data=None):
"""
Load the kernel module to be emulated
"""
pe = self.load_pe(path, data=data, imp_id=w32common.IMPORT_HOOK_ADDR)
if pe.arch == _arch.ARCH_X86:
disasm_mode = cs.CS_MODE_32
elif pe.arch == _arch.ARCH_AMD64:
disasm_mode = cs.CS_MODE_64
else:
raise KernelEmuError('Unsupported architecture: %s', pe.arch)
if not self.arch:
self.arch = pe.arch
self.set_ptr_size(self.arch)
self.emu_eng.init_engine(_arch.ARCH_X86, pe.arch)
if not self.disasm_eng:
self.disasm_eng = cs.Cs(cs.CS_ARCH_X86, disasm_mode)
self.api = WindowsApi(self)
self.om = objman.ObjectManager(emu=self)
if not data:
file_name = os.path.basename(path)
mod_name = os.path.splitext(file_name)[0]
else:
drv_hash = hashlib.sha256()
drv_hash.update(data)
drv_hash = drv_hash.hexdigest()
mod_name = drv_hash
file_name = '%s.sys' % (mod_name)
emu_path = '%sdrivers\\%s' % (self.get_system_root(), file_name)
pe.emu_path = emu_path
self.map_pe(pe, mod_name=mod_name, emu_path=emu_path)
self.mem_write(pe.base, pe.mapped_image)
# Strings the initial buffer so that we can detect decoded strings later on
if self.profiler and self.do_strings:
astrs = self.get_ansi_strings(pe.mapped_image)
wstrs = self.get_unicode_strings(pe.mapped_image)
for s in astrs:
if s not in self.profiler.strings['ansi']:
self.profiler.strings['ansi'].append(s)
for s in wstrs:
if s not in self.profiler.strings['unicode']:
self.profiler.strings['unicode'].append(s)
# Init imported data
for addr, imp in pe.imports.items():
mn, fn = imp
mod, eh = self.api.get_data_export_handler(mn, fn)
if eh:
data_ptr = self.handle_import_data(mn, fn)
sym = "%s.%s" % (mn, fn)
self.global_data.update({addr: [sym, data_ptr]})
self.mem_write(
addr, data_ptr.to_bytes(self.get_ptr_size(), 'little'))
# Set the emulator to run in protected mode
self._setup_gdt(self.get_arch())
self.setup_kernel_mode()
self.setup_user_shared_data()
if not self.stack_base:
self.stack_base, stack_ptr = self.alloc_stack(pe.stack_commit)
return pe
def pool_alloc(self, pooltype, size, tag='None'):
"""
Allocate memory in the emulated "pool"
"""
if pooltype == ddk.POOL_TYPE.NonPagedPool:
pt = 'NonPagedPool'
elif pooltype == ddk.POOL_TYPE.PagedPool:
pt = 'PagedPool'
elif pooltype == ddk.POOL_TYPE.NonPagedPoolNx:
pt = 'NonPagedPoolNx'
else:
pt = 'unk'
system_proc = self.get_system_process()
addr = self.mem_map(size,
base=None,
tag='api.pool.%s.%s' % (pt, tag),
process=system_proc)
self.pool_allocs.append((addr, pooltype, size, tag))
return addr
def init_sys_modules(self, modules_config):
"""
Initialize kernel mode modules that may be accessed by emulated modules
"""
sysmods = super(WinKernelEmulator,
self).init_sys_modules(modules_config)
# Initalize any DRIVER_OBJECTs needed by the module
for mc in modules_config:
drv = mc.get('driver')
if drv:
mod = [m for m in sysmods if m.name == mc.get('name')]
if not mod:
continue
mod = mod[0]
driver = self.create_driver_object(name=drv.get('name'),
pe=mod)
devs = drv.get('devices')
for dev in devs:
name = dev.get('name', '')
ext_size = dev.get('ext_size', 0)
devtype = dev.get('devtype', 0)
chars = dev.get('chars', 0)
self.create_device_object(name, driver, ext_size, devtype,
chars)
for m in self.modules:
mod = m[0]
sysmods.append(mod)
return sysmods
def get_processes(self):
"""
Get processes that exist in the emulation space
"""
if not self.processes:
self.init_processes(self.config_processes)
return self.processes
def init_processes(self, processes):
for proc in processes:
p = objman.Process(self)
self.add_object(p)
p.name = proc.get('name', '')
p.pid = proc.get('pid')
if p.name.lower() == 'system':
p.pid = 4
p.path = 'System'
if not p.pid:
p.pid = self.om.new_id()
base = proc.get('base_addr')
if isinstance(base, str):
base = int(base, 16)
p.base = base
if not p.path:
p.path = proc.get('path')
p.image = ntpath.basename(p.path)
# Create an initial thread for each process
t = objman.Thread(self)
self.add_object(t)
t.process = p
p.threads.append(t)
self.processes.append(p)
# The SYSTEM process should be the starting context
sp = [p for p in self.processes if p.name.lower() == 'system']
if sp:
sp = sp[0]
self.set_current_process(sp)
def alloc_peb(self, proc):
"""
Allocate PEB and related substructures for a given process
"""
ldr = proc.get_peb_ldr()
if not ldr.address:
size = ldr.sizeof()
res, size = self.get_valid_ranges(size)
base = self.mem_map(size, base=res, tag='emu.struct.PEB_LDR_DATA')
proc.set_peb_ldr_address(base)
return proc.get_peb()
def get_process_peb(self, process):
"""
Retrieve the PEB for the supplied process
"""
self.alloc_peb(process)
user_mods = self.get_user_modules()
process.init_peb(user_mods)
return process.peb
def set_current_process(self, process):
"""
Set the current process context
"""
self.curr_process = process
def get_current_process(self):
"""
Get the current process context
"""
if not self.processes:
self.processes = self.get_processes()
return self.curr_process
def run_module(self, module, all_entrypoints=False):
"""
Begin emulation fo a previously loaded kernel module
"""
self.all_entrypoints = all_entrypoints
# Create the service key for the driver
drv = self.create_driver_object(pe=module)
svc_key = self.regman.create_key(drv.get_reg_path())
# Create the values for the service key
svc_key.create_value('ImagePath', regdefs.REG_EXPAND_SZ,
module.get_emu_path())
svc_key.create_value('Type', regdefs.REG_DWORD,
0x1) # SERVICE_KERNEL_DRIVER
svc_key.create_value('Start', regdefs.REG_DWORD,
0x3) # SERVICE_DEMAND_START
svc_key.create_value('ErrorControl', regdefs.REG_DWORD,
0x1) # SERVICE_ERROR_NORMAL
# Create the parameters subkey
self.regman.create_key(drv.get_reg_path() + '\\Parameters')
if module.ep > 0:
ep = module.base + module.ep
run = Run()
run.type = EP_DRIVER_ENTRY
run.start_addr = ep
run.instr_cnt = 0
run.args = [drv.address, drv.reg_path_ptr]
self.add_run(run)
if self.all_entrypoints:
# Only emulate a subset of all the exported functions
# There are some modules (such as the windows kernel) with thousands of exports
exports = [
k for k in module.get_exports()[:MAX_EXPORTS_TO_EMULATE]
]
if exports:
args = [
self.mem_map(8, tag='emu.export_arg_%d' % (i))
for i in range(4)
]
for exp in exports:
run = Run()
if exp.name:
fn = exp.name
else:
fn = 'no_name'
run.type = 'export.%s' % (fn)
run.start_addr = exp.address
# Here we set dummy args to pass into the export function
run.args = args
# Store these runs and only queue them before the unload routine
# this is because some exports may not be ready to be called yet
self.delayed_runs.append(run)
self.start()
def create_device_object(self,
name='',
drv=0,
ext_size=0,
devtype=0,
chars=0,
tag=''):
"""
Create a device object to use for kernel emulation
"""
dev = objman.Device(self)
alloc_size = ext_size + dev.sizeof()
if not name:
devname = r'\Device\%x' % (dev.get_id())
if not tag:
tag = 'emu.device.autogen'
name = '%s.%s' % (tag, devname)
else:
devname = name
if not tag:
tag = 'emu.object'
name = '%s.%s' % (tag, devname)
dev.address = self.mem_map(alloc_size, tag=name)
dev.name = devname
# Create a FILE_OBJECT for the device
fobj = objman.FileObject(self)
dev.object.DeviceObject = dev.address
dev.file_object = fobj
self.add_object(dev)
if drv:
drv.read_back()
dev.object.DriverObject = drv.address
dev.driver = drv
if not drv.object.DeviceObject:
drv.object.DeviceObject = dev.address
drv.write_back()
else:
next_dev = self.get_object_from_addr(drv.object.DeviceObject)
while next_dev:
if next_dev.object.NextDevice:
next_dev = \
self.get_object_from_addr(drv.object.NextDevice)
else:
# This is the last in the list, add our new device
next_dev.object.NextDevice = dev.address
next_dev.write_back()
break
drv.devices.append(dev)
dev.object.Characteristics = chars
dev.object.DeviceType = devtype
if ext_size > 0:
dev.object.DeviceExtension = dev.address + dev.sizeof()
dev.write_back()
return dev
def add_symlink(self, symlink, devname):
"""
Add a symlink for a device
"""
self.om.add_symlink(symlink, devname)
def _call_driver_dispatch(self, func, dev_addr, irp_addr):
"""
Call a WDM driver dispatch function with a supplied IRP
"""
stk_ptr = self.get_stack_ptr()
self.set_func_args(stk_ptr, self.return_hook, dev_addr, irp_addr)
self.set_pc(func)
def new_irp(self):
"""
Create a new IRP
"""
return objman.Irp(emu=self)
def irp_mj_create(self, func, dev):
# Generate an IRP for the create request
irp = self.new_irp()
self._call_driver_dispatch(func, dev.address, irp.address)
return irp
def irp_mj_close(self, func, dev):
irp = self.new_irp()
self._call_driver_dispatch(func, dev.address, irp.address)
return irp
def irp_mj_dev_io(self, func, dev):
irp = self.new_irp()
ios = irp.get_curr_stack_loc()
ios.object.MajorFunction = ddk.IRP_MJ_DEVICE_CONTROL
ios.object.Parameters.DeviceIoControl.IoControlCode = 0x5d5d5d5d
ios.write_back()
irp.write_back()
self._call_driver_dispatch(func, dev.address, irp.address)
return irp
def irp_mj_read(self, func, dev):
irp = self.new_irp()
self._call_driver_dispatch(func, dev.address, irp.address)
return irp
def irp_mj_write(self, func, dev):
irp = self.new_irp()
self._call_driver_dispatch(func, dev.address, irp.address)
return irp
def irp_mj_cleanup(self, func, dev):
irp = self.new_irp()
self._call_driver_dispatch(func, dev.address, irp.address)
return irp
def driver_unload(self, drv):
"""
Call the unload routine for a driver
"""
if not drv.on_unload or drv.unload_called:
self.on_emu_complete()
return
stk_ptr = self.get_stack_ptr()
self.set_func_args(stk_ptr, self.exit_hook, drv.address)
self.set_pc(drv.on_unload)
run = Run()
run.type = EP_DRIVER_UNLOAD
run.start_addr = drv.on_unload
run.instr_cnt = 0
run.args = (drv.address, )
run.ret_val = None
self.add_run(run)
drv.unload_called = True
def next_driver_func(self, drv):
func_addr = None
func_handler = None
if self.curr_run.type is not None:
self.curr_run.ret_val = self.get_return_val()
# Check if theres anything in the run queue
if len(self.run_queue):
return
if not self.all_entrypoints:
return
# TODO right now just use the first device object that was created
dev = None
if len(drv.devices):
dev = drv.devices[0]
# Run any remaining IRP handlers
for hdlr, i in ((self.irp_mj_create, ddk.IRP_MJ_CREATE),
(self.irp_mj_dev_io, ddk.IRP_MJ_DEVICE_CONTROL),
(self.irp_mj_read, ddk.IRP_MJ_READ),
(self.irp_mj_write, ddk.IRP_MJ_WRITE),
(self.irp_mj_close, ddk.IRP_MJ_CLOSE),
(self.irp_mj_cleanup, ddk.IRP_MJ_CLEANUP)):
# Did we run this mj func yet?
if i not in [r.type for r in self.runs]:
func_handler = hdlr
func_addr = int(drv.mj_funcs[i])
if not func_addr:
continue
break
if len(self.delayed_runs):
[self.add_run(r) for r in self.delayed_runs]
self.delayed_runs = []
if not func_addr or not dev:
# We are done here, call the unload routine
self.driver_unload(drv)
return
irp = func_handler(func_addr, dev)
run = Run()
run.type = i
run.start_addr = func_addr
run.instr_cnt = 0
run.args = (dev.address, irp.address)
self.add_run(run)
def on_run_complete(self):
self.curr_run.ret_val = self.get_return_val()
for drv in self.drivers:
drv.read_back()
if drv.pe == self.curr_mod:
self.next_driver_func(drv)
# Dispatch the next run
return self._exec_next_run()
def on_emu_complete(self):
if not self.emu_complete:
self.emu_complete = True
if self.do_strings and self.profiler:
dec_ansi, dec_unicode = self.get_mem_strings()
dec_ansi = [
a for a in dec_ansi
if a not in self.profiler.strings['ansi']
]
dec_unicode = [
u for u in dec_unicode
if u not in self.profiler.strings['unicode']
]
self.profiler.decoded_strings['ansi'] = dec_ansi
self.profiler.decoded_strings['unicode'] = dec_unicode
self.stop()
def set_hooks(self):
"""Set the emulator callbacks"""
super(WinKernelEmulator, self).set_hooks()
if not self.builtin_hooks_set:
self.add_mem_invalid_hook(cb=self._hook_mem_unmapped)
self.add_interrupt_hook(cb=self._hook_interrupt)
self.builtin_hooks_set = True
self.set_mem_tracing_hooks()
def get_kernel_base(self):
"""
Get the base address of the kernel image (ntoskrnl.exe)
"""
# Get kernel base address
kern = self.get_kernel_mod()
return kern.get_base()
def get_kernel_mod(self):
"""
Get the kernel image module
"""
sys_mods = self.get_sys_modules()
for mod in sys_mods:
if mod.name.lower() == 'ntoskrnl':
return mod
raise KernelEmuError('Failed to get kernel base')
def _set_entry_point_names(self):
run_types = {
ddk.IRP_MJ_CREATE: 'irp_mj_create',
ddk.IRP_MJ_DEVICE_CONTROL: 'irp_mj_device_control',
ddk.IRP_MJ_READ: 'irp_mj_read',
ddk.IRP_MJ_WRITE: 'irp_mj_write',
ddk.IRP_MJ_CLOSE: 'irp_mj_close',
ddk.IRP_MJ_CLEANUP: 'irp_mj_cleanup',
EP_DRIVER_ENTRY: 'entry_point',
EP_DRIVER_UNLOAD: 'driver_unload'
}
for r in self.runs:
if not r.type or run_types.get(r.type):
r.type = run_types.get(r.type, 'unk')
def get_report(self):
""" Retrieve the execution profile for the emulator """
self._set_entry_point_names()
return super(WinKernelEmulator, self).get_report()
def get_json_report(self):
self._set_entry_point_names()
return super(WinKernelEmulator, self).get_json_report()
def get_ssdt_ptr(self):
return self.ssdt_ptr
def setup_kernel_mode(self):
idt = objman.IDT(self)
idt.init_descriptors()
# selector, base, limit, flags
self.reg_write(_arch.X86_REG_IDTR,
(0, idt.object.Descriptors, idt.object.Limit, 0))
# Setup the SSDT
ssdt = self.ktypes.SSDT(self.get_ptr_size())
size = self.get_ptr_size() * 256
self.ssdt_ptr = self.mem_map(size, base=None, tag='api.struct.SSDT')
ssdt.NumberOfServices = 256
ssdt.pServiceTable = self.ssdt_ptr + self.sizeof(ssdt)
self.mem_write(self.ssdt_ptr, self.get_bytes(ssdt))
self.get_sys_modules()
self.setup_msrs()
for sl in self.symlinks:
self.om.add_symlink(sl['name'], sl['target'])
def setup_msrs(self):
"""
Setup machine specific registers for kernel emulation
"""
# Initalize the LSTAR on amd64 with the address of KiSystemCall64
km = self.get_kernel_mod()
if self.get_arch() == _arch.ARCH_AMD64:
ksc64_off = km.find_bytes(b'\x00' * 100, 0)
if ksc64_off != -1:
self.map_decoy(km)
sdt = km.get_export_by_name('KeServiceDescriptorTable')
if sdt:
kbase = km.get_base()
sdt_addr = kbase + sdt
# Set the symbols up
for i in range(0x20):
self.symbols.update({
sdt_addr + i:
(km.get_base_name(), 'KeServiceDescriptorTable')
})
self.symbols.update({
sdt_addr: (km.get_base_name(),
'KeServiceDescriptorTable.pServiceTable')
})
self.symbols.update({
sdt_addr + 0x10:
(km.get_base_name(),
'KeServiceDescriptorTable.NumberOfServices')
})
ksc64_off += 5
ksc64_addr = kbase + ksc64_off
self.symbols.update(
{ksc64_addr: (km.get_base_name(), 'KiSystemCall64')})
# Write the address of our fake KiSystemCall64 to the LSTAR register
self.reg_write(_arch.X86_REG_MSR,
(_arch.LSTAR, ksc64_addr))
# ssdt load:
# KeServiceDescriptorTable
sdt_offset = (sdt_addr - ksc64_addr) - 7
data = b'\x90\x90\xc3' + sdt_offset.to_bytes(4, 'little')
self.mem_write(kbase + ksc64_off, data)
ksc64_off += 7
# shadow_ssdt_load:
# KeServiceDescriptorTableShadow
sdt_offset = sdt_addr - (kbase + ksc64_off)
data = b'\x90\x90\xc3' + sdt_offset.to_bytes(4, 'little')
km.set_bytes(ksc64_off, data)
ksc64_off += 7
data = b'\x90\x90\x90\x90\x90\x90\xc3'
km.set_bytes(ksc64_off, data)