emu.set_memory(codebase + x, int(ord(c)), size=1)
print "[*] Text section loaded into memory"
print "[*] Loading data section bytes into memory"
for x in range(len(datasection.data)):
c = datasection.data[x]
emu.set_memory(database + x, int(ord(c)), size=1)
print "[*] Data section loaded into memory\n"
emu.set_register("EIP", address)
#emu.set_stack_variable(0x10, 0x00000000, name="var_10")
#emu.set_stack_variable(0x0c, 0x11111111, name="var_c")
#emu.set_stack_variable(0x08, 0x22222222, name="var_8")
#emu.set_stack_variable(0x04, 0x33333333, name="var_4")
emu.set_stack_argument(0x8, 0x10, name="arg_0")
emu.set_stack_argument(0xc, 0x20, name="arg_4")
c = None
while c != "x":
if not emu.execute():
sys.exit(-1)
emu.dump_regs()
c = raw_input("emulator> ")
fh.write("%c" % emu.get_memory(base+x, 1))
print "[*] Dumping UPX1 Section"
base = emu.sections["UPX1"]["base"]
length = emu.sections["UPX1"]["vsize"]
print "[*] Base: 0x%08x Vsize: %08x" % (base, length)
for x in range(length):
fh.write("%c" % emu.get_memory(base+x, 1))
print "[*] Finished."
exename = sys.argv[1]
outputfile = sys.argv[2]
emu = PEPyEmu()
if exename:
if not emu.load(exename):
print "[!] Problem loading %s" % exename
sys.exit(2)
else:
print "[!] Blank filename specified"
sys.exit(3)
emu.set_library_handler("LoadLibraryA", loadlibrary)
emu.set_library_handler("GetProcAddress", getprocaddress)
emu.set_library_handler("VirtualProtect", virtualprotect)
emu.set_mnemonic_handler("jmp", jmp_handler)
emu.execute(start=emu.entry_point, end=0xFFFFFFFF)
database = 0x40d000
print len(datasection.data)
for y in range(len(datasection.data)):
c = datasection.data[y]
#print "0x%08x"%(database + x + y)
if int(ord(c)) == 0xbb:
print "#################0x%08x"%(database+x+y)
emu.set_memory(database + y, int(ord(c)), size=1)
print "[*] Data section loaded into memory\n"
print "%08x"%emu.get_register("EIP")
print "%08x"%address
emu.set_register("EIP", address)
print "%08x"%emu.get_register("EIP")
#emu.set_stack_variable(0x10, 0x00000000, name="var_10")
#emu.set_stack_variable(0x0c, 0x11111111, name="var_c")
#emu.set_stack_variable(0x08, 0x22222222, name="var_8")
#emu.set_stack_variable(0x04, 0x33333333, name="var_4")
emu.set_stack_argument(0x8, 0x10, name="arg_0")
emu.set_stack_argument(0xc, 0x20, name="arg_4")
c = None
while c != "x":
if not emu.execute():
sys.exit(-1)
emu.dump_regs()
c = raw_input("emulator> ")
print "[*] Finished."
# Commandline arguments
exename = sys.argv[1]
outputfile = sys.argv[2]
# Instantiate our emulator object
emu = PEPyEmu()
if exename:
# Load the binary into PyEmu
if not emu.load(exename):
print "[!] Problem loading %s" % exename
sys.exit(2)
else:
print "[!] Blank filename specified"
sys.exit(3)
# Set our library handlers
emu.set_library_handler("LoadLibraryA", loadlibrary)
emu.set_library_handler("GetProcAddress", getprocaddress)
emu.set_library_handler("VirtualProtect", virtualprotect)
# Set a breakpoint at the real entry point to dump binary
emu.set_mnemonic_handler("jmp", jmp_handler)
# Execute starting from the header entry point
emu.execute(start=emu.entry_point)
class AVEngine:
def __init__(self):
self.imagebase = 0
self.codebase = 0
self.database = 0
self.bytesobs =0
self.deobsbytes=0
self.entrypoint =0
self.pe = 0
self.emu=0
self.obsfucated=0
def SearchString(self,text, pattern, no_of_split):
patterns=pattern.split("*", no_of_split)
for pattern in patterns:
offset = text.find(pattern)
if(offset == -1):
print "not found" ,hex(ord(pattern[0])), offset
return 0
text= text[offset+len(pattern):]
return 1
def init(self ,filename):
if filename:
self.pe = pefile.PE(filename)
else:
print "[!] Blank filename specified"
sys.exit(2)
self.imagebase = self.pe.OPTIONAL_HEADER.ImageBase
self.codebase = self.pe.OPTIONAL_HEADER.ImageBase + self.pe.OPTIONAL_HEADER.BaseOfCode
self.database = self.pe.OPTIONAL_HEADER.ImageBase + self.pe.OPTIONAL_HEADER.BaseOfData
self.entrypoint = self.pe.OPTIONAL_HEADER.ImageBase + self.pe.OPTIONAL_HEADER.AddressOfEntryPoint
print "[*] Image Base Addr: 0x%08x" % (self.imagebase)
print "[*] Code Base Addr: 0x%08x" % (self.codebase)
print "[*] Data Base Addr: 0x%08x" % (self.database)
print "[*] Entry Point Addr: 0x%08x\n" % (self.entrypoint)
self.emu = PEPyEmu()
def isfileobsfucated(self):
ep = self.pe.OPTIONAL_HEADER.AddressOfEntryPoint
ep_ava = ep+self.pe.OPTIONAL_HEADER.ImageBase
data = self.pe.get_memory_mapped_image()[ep:ep+40]
#idata = array.array('B', [0xb9,0x5a,0x01,0x00,0x00,0x43,0x4b,0xbe,0x00,0x10,0x40,0x00,0xb3,0xa6,0x8a,0x16,0x32,0xd3])
idata = array.array('B', [0xB9,0x2A,0xBE,0x2A,0xB3,0x2A,0x8A,0x16,0x32,0xD3,0x8A,0x1E,0x88,0x16,0x46,0xE2,0x2A,0xE9])
signature = idata.tostring()
#ret= data.find(data,signature,4)
ret= self.SearchString(data,signature,5)
#print "Signature " ,ret
self.obsfucated = ret
return ret
def initalizesections(self):
for section in self.pe.sections:
if section.Name.startswith(".text"):
textsection = section
elif section.Name.startswith(".rdata"):
datasection = section
self.codelen = len(textsection.data)
for x in range(len(textsection.data)):
c = textsection.data[x]
self.emu.set_memory(self.codebase + x, int(ord(c)), size=1)
self.datalen = len(datasection.data)
for x in range(len(datasection.data)):
c = datasection.data[x]
self.emu.set_memory(self.database + x, int(ord(c)), size=1)
self.emu.set_stack_argument(0x8, 0x10, name="arg_0")
self.emu.set_stack_argument(0xc, 0x20, name="arg_4")
def checkmalware(self) :
if(self.obsfucated) :
self.deobsbytes =abs(self.bytesobs-(self.emu.get_register("EIP")-self.codebase))
#print "diff " , diff
exec_code =self.emu.get_memory(self.emu.get_register("EIP") ,self.deobsbytes )
#print hex(ord(exec_code[0]))
else :
self.initalizesections()
exec_code = self.emu.get_memory(self.codebase ,self.codelen )
idata = array.array('B', [0x68,0x2A,0x6A,0x01,0x6A,0x00,0xE8])
signature = idata.tostring()
ret = self.SearchString(exec_code,signature,2)
if ret :
print "bad code "
else:
print "good code "
def deobsfucate(self) :
self.initalizesections()
ep = self.pe.OPTIONAL_HEADER.AddressOfEntryPoint
ep_ava = ep+self.pe.OPTIONAL_HEADER.ImageBase
data = self.pe.get_memory_mapped_image()[ep:ep+40]
offset=0
self.emu.set_register("EIP", self.entrypoint)
self.emu.set_register("ECX", 0x00000000)
self.emu.set_register("BL", 0x00)
self.emu.set_register("DL", 0x00)
instruction = "NOP"
while not instruction.startswith("loop") : #offset < len(data):
i = pydasm.get_instruction(data[offset:], pydasm.MODE_32)
instruction=pydasm.get_instruction_string(i, pydasm.FORMAT_INTEL, ep_ava+offset)
offset+=i.length
print instruction
#c = raw_input("emulator> ")
while 1 :
value1 = self.emu.get_register("ECX")
value2 = self.emu.get_register("BL")
value3 = self.emu.get_register("DL")
if(value1 != 0 and value2 !=0 and value3 != 0):
break;
self.emu.execute()
self.bytesobs = value1
byte_obs = value1
while value1 !=0:
self.emu.execute()
value1 =self.emu.get_register("ECX")
i = pydasm.get_instruction(data[offset:], pydasm.MODE_32)
instruction=pydasm.get_instruction_string(i, pydasm.FORMAT_INTEL, ep_ava+offset)
print instruction
offset+=i.length
self.emu.execute()
#offset+=((ep_ava+offset)- emu.get_register("EIP"))
nxt_offset = self.emu.get_register("EIP")- (ep_ava+offset)
offset+=nxt_offset
instruction = "nop"
while not instruction.startswith("jmp") : # offset < len(data)
i = pydasm.get_instruction(data[offset:], pydasm.MODE_32)
instruction=pydasm.get_instruction_string(i, pydasm.FORMAT_INTEL, ep_ava+offset)
self.emu.execute()
offset+=i.length
print instruction
#c = raw_input("emulator> ")
ret=instruction.find("0x")
jmp_address= instruction[ret+2:]
def findObsSignature(filename):
if filename:
pe = pefile.PE(filename)
else:
print "[!] Blank filename specified"
sys.exit(2)
imagebase = pe.OPTIONAL_HEADER.ImageBase
codebase = pe.OPTIONAL_HEADER.ImageBase + pe.OPTIONAL_HEADER.BaseOfCode
database = pe.OPTIONAL_HEADER.ImageBase + pe.OPTIONAL_HEADER.BaseOfData
entrypoint = pe.OPTIONAL_HEADER.ImageBase + pe.OPTIONAL_HEADER.AddressOfEntryPoint
print "[*] Image Base Addr: 0x%08x" % (imagebase)
print "[*] Code Base Addr: 0x%08x" % (codebase)
print "[*] Data Base Addr: 0x%08x" % (database)
print "[*] Entry Point Addr: 0x%08x\n" % (entrypoint)
ep = pe.OPTIONAL_HEADER.AddressOfEntryPoint
ep_ava = ep+pe.OPTIONAL_HEADER.ImageBase
data = pe.get_memory_mapped_image()[ep:ep+40]
offset=0
#idata = array.array('B', [0xb9,0x5a,0x01,0x00,0x00,0x43,0x4b,0xbe,0x00,0x10,0x40,0x00,0xb3,0xa6,0x8a,0x16,0x32,0xd3])
idata = array.array('B', [0xB9,0x2A,0xBE,0x2A,0xB3,0x2A,0x8A,0x16,0x32,0xD3,0x8A,0x1E,0x88,0x16,0x46,0xE2,0x2A,0xE9])
signature = idata.tostring()
#ret= data.find(data,signature,4)
ret= SearchString(data,signature,5)
print "Signature " ,ret
emu = PEPyEmu()
#emu.debug(1)
for section in pe.sections:
if section.Name.startswith(".text"):
textsection = section
elif section.Name.startswith(".rdata"):
datasection = section
for x in range(len(textsection.data)):
c = textsection.data[x]
emu.set_memory(codebase + x, int(ord(c)), size=1)
for x in range(len(datasection.data)):
c = datasection.data[x]
emu.set_memory(database + x, int(ord(c)), size=1)
ep = pe.OPTIONAL_HEADER.AddressOfEntryPoint
ep_ava = ep+pe.OPTIONAL_HEADER.ImageBase
data = pe.get_memory_mapped_image()[ep:ep+40]
emu.set_stack_argument(0x8, 0x10, name="arg_0")
emu.set_stack_argument(0xc, 0x20, name="arg_4")
if (ret):
offset=0
emu.set_register("EIP", entrypoint)
emu.set_register("ECX", 0x00000000)
emu.set_register("BL", 0x00)
emu.set_register("DL", 0x00)
instruction = "NOP"
while not instruction.startswith("loop") : #offset < len(data):
i = pydasm.get_instruction(data[offset:], pydasm.MODE_32)
instruction=pydasm.get_instruction_string(i, pydasm.FORMAT_INTEL, ep_ava+offset)
offset+=i.length
print instruction
#c = raw_input("emulator> ")
while 1 :
value1 = emu.get_register("ECX")
value2 = emu.get_register("BL")
value3 = emu.get_register("DL")
if(value1 != 0 and value2 !=0 and value3 != 0):
break;
emu.execute()
byte_obs = value1
while value1 !=0:
emu.execute()
value1 =emu.get_register("ECX")
i = pydasm.get_instruction(data[offset:], pydasm.MODE_32)
instruction=pydasm.get_instruction_string(i, pydasm.FORMAT_INTEL, ep_ava+offset)
print instruction
offset+=i.length
emu.execute()
#offset+=((ep_ava+offset)- emu.get_register("EIP"))
print "after jump"
resu = emu.get_register("EIP")- (ep_ava+offset)
print " %x " % resu
print "%x" % emu.get_register("EIP")
offset+=resu
instruction = "nop"
while not instruction.startswith("jmp") : #offset < len(data):
if ord(data[0]) == 0x90:
print "nop"
i = pydasm.get_instruction(data[offset:], pydasm.MODE_32)
print "i " , i
instruction=pydasm.get_instruction_string(i, pydasm.FORMAT_INTEL, ep_ava+offset)
emu.execute()
offset+=i.length
print instruction
#c = raw_input("emulator> ")
ret=instruction.find("0x")
jmp_address= instruction[ret+2:]
#print "ret " , ret, hex(jmp_address)
#emu.execute()
#emu.execute()
#print " I am here1 "
emu.dump_regs()
diff =abs(byte_obs-(emu.get_register("EIP")-codebase))
print "diff " , diff
exec_code =emu.get_memory(emu.get_register("EIP") ,diff )
print hex(ord(exec_code[0]))
idata = array.array('B', [0x68,0x2A,0x6A,0x01,0x6A,0x00,0xE8])
signature = idata.tostring()
ret = SearchString(exec_code,signature,2)
if ret :
print "bad code "
else:
print "good code "
print "[!] Problem loading %s" % exename
sys.exit(2)
else:
print "[!] Blank filename specified"
sys.exit(3)
# Set our library handlers
emu.set_library_handler("LoadLibraryA", loadlibrary)
emu.set_library_handler("GetProcAddress", getprocaddress)
emu.set_library_handler("VirtualProtect", virtualprotect)
# Set a breakpoint at the real entry point to dump binary
emu.set_mnemonic_handler( "jmp", jmp_handler )
# Execute starting from the header entry point
emu.execute( start=emu.entry_point )
'''
HMODULE WINAPI LoadLibrary(
__in LPCTSTR lpFileName
);
'''
def loadlibrary(name, address):
# Retrieve the DLL name
dllname = emu.get_memory_string(emu.get_memory(emu.get_register("ESP") + 4))
# Make a real call to LoadLibrary and return the handle
dllhandle = windll.kernel32.LoadLibraryA(dllname)
emu.set_register("EAX", dllhandle)
