pyinstxtractor 源码分析及填坑
pyinstxtractor 是一个用来反编译PyInstaller打包成的EXE的脚本。
PyInstaller：python脚本---》生成EXE，可脱离python环境运行。
pyinstxtractor: EXE--》python脚本，即还原出上述脚本。
pyinstxtractor 下载地址：
https://github.com/extremecoders-re/pyinstxtractor
"""
PyInstaller Extractor v2.0 (Supports pyinstaller 3.6, 3.5, 3.4, 3.3, 3.2, 3.1, 3.0, 2.1, 2.0)
Author : Extreme Coders
E-mail : extremecoders(at)hotmail(dot)com
Web : https://0xec.blogspot.com
Date : 26-March-2020
Url : https://github.com/extremecoders-re/pyinstxtractor
For any suggestions, leave a comment on
https://forum.tuts4you.com/topic/34455-pyinstaller-extractor/
This script extracts a pyinstaller generated executable file.
Pyinstaller installation is not needed. The script has it all.
For best results, it is recommended to run this script in the
same version of python as was used to create the executable.
This is just to prevent unmarshalling errors(if any) while
extracting the PYZ archive.
Usage : Just copy this script to the directory where your exe resides
and run the script with the exe file name as a parameter
C:\path\to\exe\>python pyinstxtractor.py
$ /path/to/exe/python pyinstxtractor.py
Licensed under GNU General Public License (GPL) v3.
You are free to modify this source.
CHANGELOG
================================================
Version 1.1 (Jan 28, 2014)
-------------------------------------------------
- First Release
- Supports only pyinstaller 2.0
Version 1.2 (Sept 12, 2015)
-------------------------------------------------
- Added support for pyinstaller 2.1 and 3.0 dev
- Cleaned up code
- Script is now more verbose
- Executable extracted within a dedicated sub-directory
(Support for pyinstaller 3.0 dev is experimental)
Version 1.3 (Dec 12, 2015)
-------------------------------------------------
- Added support for pyinstaller 3.0 final
- Script is compatible with both python 2.x & 3.x (Thanks to Moritz Kroll @ Avira Operations GmbH & Co. KG)
Version 1.4 (Jan 19, 2016)
-------------------------------------------------
- Fixed a bug when writing pyc files >= version 3.3 (Thanks to Daniello Alto: https://github.com/Djamana)
Version 1.5 (March 1, 2016)
-------------------------------------------------
- Added support for pyinstaller 3.1 (Thanks to Berwyn Hoyt for reporting)
Version 1.6 (Sept 5, 2016)
-------------------------------------------------
- Added support for pyinstaller 3.2
- Extractor will use a random name while extracting unnamed files.
- For encrypted pyz archives it will dump the contents as is. Previously, the tool would fail.
Version 1.7 (March 13, 2017)
-------------------------------------------------
- Made the script compatible with python 2.6 (Thanks to Ross for reporting)
Version 1.8 (April 28, 2017)
-------------------------------------------------
- Support for sub-directories in .pyz files (Thanks to Moritz Kroll @ Avira Operations GmbH & Co. KG)
Version 1.9 (November 29, 2017)
-------------------------------------------------
- Added support for pyinstaller 3.3
- Display the scripts which are run at entry (Thanks to Michael Gillespie @ malwarehunterteam for the feature request)
Version 2.0 (March 26, 2020)
-------------------------------------------------
- Project migrated to github
- Supports pyinstaller 3.6
- Added support for Python 3.7, 3.8
- The header of all extracted pyc's are now automatically fixed
"""
from __future__ import print_function
import os
import struct
import marshal
import zlib
import sys
from uuid import uuid4 as uniquename
# imp is deprecated in Python3 in favour of importlib
if sys.version_info.major == 3:
from importlib.util import MAGIC_NUMBER
pyc_magic = MAGIC_NUMBER
else:
import imp
pyc_magic = imp.get_magic()
class CTOCEntry:
def __init__(self, position, cmprsdDataSize, uncmprsdDataSize, cmprsFlag, typeCmprsData, name):
self.position = position
self.cmprsdDataSize = cmprsdDataSize
self.uncmprsdDataSize = uncmprsdDataSize
self.cmprsFlag = cmprsFlag
self.typeCmprsData = typeCmprsData
self.name = name
class PyInstArchive:
PYINST20_COOKIE_SIZE = 24 # For pyinstaller 2.0
PYINST21_COOKIE_SIZE = 24 + 64 # For pyinstaller 2.1+
MAGIC = b'MEI\014\013\012\013\016' # Magic number which identifies pyinstaller
def __init__(self, path):
self.filePath = path
def open(self):
try:
self.fPtr = open(self.filePath, 'rb')
self.fileSize = os.stat(self.filePath).st_size
except:
print('[!] Error: Could not open {0}'.format(self.filePath))
return False
return True
def close(self):
try:
self.fPtr.close()
except:
pass
def checkFile(self):
print('[+] Processing {0}'.format(self.filePath))
# Check if it is a 2.0 archive
self.fPtr.seek(self.fileSize - self.PYINST20_COOKIE_SIZE, os.SEEK_SET)
magicFromFile = self.fPtr.read(len(self.MAGIC))
if magicFromFile == self.MAGIC:
self.pyinstVer = 20 # pyinstaller 2.0
print('[+] Pyinstaller version: 2.0')
return True
# Check for pyinstaller 2.1+ before bailing out
self.fPtr.seek(self.fileSize - self.PYINST21_COOKIE_SIZE, os.SEEK_SET)
magicFromFile = self.fPtr.read(len(self.MAGIC))
if magicFromFile == self.MAGIC:
print('[+] Pyinstaller version: 2.1+')
self.pyinstVer = 21 # pyinstaller 2.1+
return True
print('[!] Error : Unsupported pyinstaller version or not a pyinstaller archive')
return False
def getCArchiveInfo(self):
try:
if self.pyinstVer == 20:
self.fPtr.seek(self.fileSize - self.PYINST20_COOKIE_SIZE, os.SEEK_SET)
# Read CArchive cookie
(magic, lengthofPackage, toc, tocLen, self.pyver) = \
struct.unpack('!8siiii', self.fPtr.read(self.PYINST20_COOKIE_SIZE))
elif self.pyinstVer == 21:
self.fPtr.seek(self.fileSize - self.PYINST21_COOKIE_SIZE, os.SEEK_SET)
# Read CArchive cookie
(magic, lengthofPackage, toc, tocLen, self.pyver, pylibname) = \
struct.unpack('!8siiii64s', self.fPtr.read(self.PYINST21_COOKIE_SIZE))
except:
print('[!] Error : The file is not a pyinstaller archive')
return False
print('[+] Python version: {0}'.format(self.pyver))
# Overlay is the data appended at the end of the PE
self.overlaySize = lengthofPackage
self.overlayPos = self.fileSize - self.overlaySize
self.tableOfContentsPos = self.overlayPos + toc
self.tableOfContentsSize = tocLen
print('[+] Length of package: {0} bytes'.format(self.overlaySize))
return True
def parseTOC(self):
# Go to the table of contents
self.fPtr.seek(self.tableOfContentsPos, os.SEEK_SET)
self.tocList = []
parsedLen = 0
# Parse table of contents
while parsedLen < self.tableOfContentsSize:
(entrySize, ) = struct.unpack('!i', self.fPtr.read(4))
nameLen = struct.calcsize('!iiiiBc')
(entryPos, cmprsdDataSize, uncmprsdDataSize, cmprsFlag, typeCmprsData, name) = \
struct.unpack( \
'!iiiBc{0}s'.format(entrySize - nameLen), \
self.fPtr.read(entrySize - 4))
name = name.decode('utf-8').rstrip('\0')
if len(name) == 0:
name = str(uniquename())
print('[!] Warning: Found an unamed file in CArchive. Using random name {0}'.format(name))
self.tocList.append( \
CTOCEntry( \
self.overlayPos + entryPos, \
cmprsdDataSize, \
uncmprsdDataSize, \
cmprsFlag, \
typeCmprsData, \
name \
))
parsedLen += entrySize
print('[+] Found {0} files in CArchive'.format(len(self.tocList)))
def _writeRawData(self, filepath, data):
nm = filepath.replace('\\', os.path.sep).replace('/', os.path.sep).replace('..', '__')
nmDir = os.path.dirname(nm)
if nmDir != '' and not os.path.exists(nmDir): # Check if path exists, create if not
os.makedirs(nmDir)
with open(nm, 'wb') as f:
f.write(data)
def extractFiles(self):
print('[+] Beginning extraction...please standby')
extractionDir = os.path.join(os.getcwd(), os.path.basename(self.filePath) + '_extracted')
if not os.path.exists(extractionDir):
os.mkdir(extractionDir)
os.chdir(extractionDir)
for entry in self.tocList:
basePath = os.path.dirname(entry.name)
if basePath != '':
# Check if path exists, create if not
if not os.path.exists(basePath):
os.makedirs(basePath)
self.fPtr.seek(entry.position, os.SEEK_SET)
data = self.fPtr.read(entry.cmprsdDataSize)
if entry.cmprsFlag == 1:
data = zlib.decompress(data)
# Malware may tamper with the uncompressed size
# Comment out the assertion in such a case
assert len(data) == entry.uncmprsdDataSize # Sanity Check
if entry.typeCmprsData == b's':
# s -> ARCHIVE_ITEM_PYSOURCE
# Entry point are expected to be python scripts
print('[+] Possible entry point: {0}.pyc'.format(entry.name))
self._writePyc(entry.name + '.pyc', data)
elif entry.typeCmprsData == b'M' or entry.typeCmprsData == b'm':
# M -> ARCHIVE_ITEM_PYPACKAGE
# m -> ARCHIVE_ITEM_PYMODULE
# packages and modules are pyc files with their header's intact
self._writeRawData(entry.name + '.pyc', data)
else:
self._writeRawData(entry.name, data)
if entry.typeCmprsData == b'z' or entry.typeCmprsData == b'Z':
self._extractPyz(entry.name)
def _writePyc(self, filename, data):
with open(filename, 'wb') as pycFile:
pycFile.write(pyc_magic) # pyc magic
if self.pyver >= 37: # PEP 552 -- Deterministic pycs
pycFile.write(b'\0' * 4) # Bitfield
pycFile.write(b'\0' * 8) # (Timestamp + size) || hash
else:
pycFile.write(b'\0' * 4) # Timestamp
if self.pyver >= 33:
pycFile.write(b'\0' * 4) # Size parameter added in Python 3.3
pycFile.write(data)
def _extractPyz(self, name):
dirName = name + '_extracted'
# Create a directory for the contents of the pyz
if not os.path.exists(dirName):
os.mkdir(dirName)
with open(name, 'rb') as f:
pyzMagic = f.read(4)
assert pyzMagic == b'PYZ\0' # Sanity Check
pycHeader = f.read(4) # Python magic value
# Skip PYZ extraction if not running under the same python version
if pyc_magic != pycHeader:
print('[!] Warning: This script is running in a different Python version than the one used to build the executable.')
print('[!] Please run this script in Python{0} to prevent extraction errors during unmarshalling'.format(self.pyver))
print('[!] Skipping pyz extraction')
return
(tocPosition, ) = struct.unpack('!i', f.read(4))
f.seek(tocPosition, os.SEEK_SET)
try:
toc = marshal.load(f)
except:
print('[!] Unmarshalling FAILED. Cannot extract {0}. Extracting remaining files.'.format(name))
return
print('[+] Found {0} files in PYZ archive'.format(len(toc)))
# From pyinstaller 3.1+ toc is a list of tuples
if type(toc) == list:
toc = dict(toc)
for key in toc.keys():
(ispkg, pos, length) = toc[key]
f.seek(pos, os.SEEK_SET)
fileName = key
try:
# for Python > 3.3 some keys are bytes object some are str object
fileName = fileName.decode('utf-8')
except:
pass
# Prevent writing outside dirName
fileName = fileName.replace('..', '__').replace('.', os.path.sep)
if ispkg == 1:
filePath = os.path.join(dirName, fileName, '__init__.pyc')
else:
filePath = os.path.join(dirName, fileName + '.pyc')
fileDir = os.path.dirname(filePath)
if not os.path.exists(fileDir):
os.makedirs(fileDir)
try:
data = f.read(length)
data = zlib.decompress(data)
except:
print('[!] Error: Failed to decompress {0}, probably encrypted. Extracting as is.'.format(filePath))
open(filePath + '.encrypted', 'wb').write(data)
else:
self._writePyc(filePath, data)
def main():
if len(sys.argv) < 2:
print('[+] Usage: pyinstxtractor.py ')
else:
arch = PyInstArchive(sys.argv[1])
if arch.open():
if arch.checkFile():
if arch.getCArchiveInfo():
arch.parseTOC()
arch.extractFiles()
arch.close()
print('[+] Successfully extracted pyinstaller archive: {0}'.format(sys.argv[1]))
print('')
print('You can now use a python decompiler on the pyc files within the extracted directory')
return
arch.close()
if __name__ == '__main__':
main() 此脚本使用很简单,命令行下脚本后边跟上要解包的文件即可。
下边以python3.8 打包的程序为例;
PyInstArchive类解析：
def __init__(self, path): 初始化函数，将命令行传入的路径保存到成员filepath中。
def open(self): 以二进制文件方式打开文件，并保存文件指针及文件大小到成员变量 fptr 和 filesize中
文件大小：9,930,109 0x97857D
def close(self): 文件指针关闭
def checkFile(self): 判断是否是pyinstall打包的程序以及打包程序版本。
Pyinstaller version: 2.0 文件倒数第24个字节处为标志字符串 'MEI\014\013\012\013\016'
Pyinstaller version: 2.1+ 2.1以后的版本 文件倒数第88(=24+64)个字节处为标志字符串 'MEI\014\013\012\013\016'
尾部数据：
阴影部分即为尾部的结构数据部分。
def getCArchiveInfo(self): 解析尾部的结构 这个是大端序
Pyinstaller version: 2.0
magic 偏移0 长度8 标志字符串 MEI。。。。。
lengthofPackage 偏移 8 长度4 附加数据大小 0x0093c97d
toc 偏移12 长度4 0x00930A15 //附件数据起始位置(overlayPos )为0x0x3bc00
tocLen, 偏移16 长度 4 0xBF10 //tableOfContentsPos=0x96c615
self.pyver 偏移20 长度 4 0x26
2.1以上版本跟这个大同小异，只不过多了一个pylibname 这里文件名为python38.dll
def parseTOC(self): 解析文件
1.定位到 tableOfContentsPos 0x96c615 上图中从阴影开始的位置
(entrySize, ) = struct.unpack('!i', self.fPtr.read(4))
#计算给定的格式(fmt)占用多少字节的内存 namelen=18
nameLen = struct.calcsize('!iiiiBc')
(entryPos, cmprsdDataSize, uncmprsdDataSize, cmprsFlag, typeCmprsData, name) = \
struct.unpack( \
'!iiiBc{0}s'.format(entrySize - nameLen), \
self.fPtr.read(entrySize - 4))
name = name.decode('utf-8').rstrip('\0')上图中带阴影部分为第一个结构 。
entrySize =0x20
entrypos=0
cmprsdDataSize=0x105 压缩后大小
uncmprsdDataSize=0x157 压缩前大小
cmprsFlag=1 压缩标志
typeCmprsData=0x6D // 这个不同的值对应不同的含义,具体含义下下文：
s 0x73 Entry point are expected to be python scripts 入口python文件
m 0x6D packages and modules are pyc files with their header's intact m -> ARCHIVE_ITEM_PYMODULE
M 0x4D M -> ARCHIVE_ITEM_PYPACKAGE
Z
z
name 长度为0x20-18=14 字符为 struct
绿色线为下一个结构
红色线+灰色线是再下一个结构
def _writeRawData(self, filepath, data): 写文件
def extractFiles(self): 提取文件 根据 parseTOC 函数中提取的文件结构写文件
def _writePyc(self, filename, data): 写pyc文件，坑就是再这里
#坑在这
# imp is deprecated in Python3 in favour of importlib
if sys.version_info.major == 3:
from importlib.util import MAGIC_NUMBER
pyc_magic = MAGIC_NUMBER
else:
import imp
pyc_magic = imp.get_magic()
def _writePyc(self, filename, data):
with open(filename, 'wb') as pycFile:
pycFile.write(pyc_magic) # pyc magic
if self.pyver >= 37: # PEP 552 -- Deterministic pycs
pycFile.write(b'\0' * 4) # Bitfield
pycFile.write(b'\0' * 8) # (Timestamp + size) || hash
else:
pycFile.write(b'\0' * 4) # Timestamp
if self.pyver >= 33:
pycFile.write(b'\0' * 4) # Size parameter added in Python 3.3
pycFile.write(data)
这个函数不复杂，就是先写入pyc文件的头部结构，然后写入后边的数据。而坑就在pyc_magic 这里，此脚本在写入头部的四字节时不是按照解析文件的版本写入标志字节，而是直接读取当前环境下的头部magic进行写入。
例如 环境是 3.8 那 pyc_magic 就是 ’\x55\x0d\x0d\x0a‘ 不管你解析的程序中python版本是多少。
环境是 2.7 那 pyc_magic 就是 ’\x03\xf3\x0d\x0a‘ 不管你解析的程序中python版本是多少。
在此例中，作者环境为python3.8 而此exe的版本正好也是3.8 所以解出来的pyc可以顺利反编译。
假如作者环境时2.7 那解包出来的pyc就没法反编译。
https://github.com/zrax/pycdc/blob/master/PythonBytecode.txt
各版本对应的magic如下，下表为小端序。如果时3.8 实际应写入 ’\x55\x0d\x0d\x0a‘
Python MAGIC Python MAGIC Python MAGIC
1.0 0x00999902 2.0 0x0A0DC687 3.0 0x0A0D0C3A
1.1 0x00999903 2.1 0x0A0DEB2A 3.1 0x0A0D0C4E
1.2 0x00999903 2.2 0x0A0DED2D 3.2 0x0A0D0C6C
1.3 0x0A0D2E89 2.3 0x0A0DF23B 3.3 0x0A0D0C9E
1.4 0x0A0D1704 2.4 0x0A0DF26D 3.4 0x0A0D0CEE
1.5 0x0A0D4E99 2.5 0x0A0DF2B3 3.5 0x0A0D0D16
1.6 0x0A0DC4FC 2.6 0x0A0DF2D1 3.5.3 0x0A0D0D17
2.7 0x0A0DF303 3.6 0x0A0D0D33
3.7 0x0A0D0D42
3.8 0x0A0D0D55def _extractPyz(self, name): 写PYZ文件的
源码解析到此结束。
需要填坑的函数就是
def _writePyc(self, filename, data):
with open(filename, 'wb') as pycFile:
pycFile.write(pyc_magic) # pyc magic//pyc_magic 需要改为根据self.pyver 查下表写入。
Python MAGIC Python MAGIC Python MAGIC
1.0 0x00999902 2.0 0x0A0DC687 3.0 0x0A0D0C3A
1.1 0x00999903 2.1 0x0A0DEB2A 3.1 0x0A0D0C4E
1.2 0x00999903 2.2 0x0A0DED2D 3.2 0x0A0D0C6C
1.3 0x0A0D2E89 2.3 0x0A0DF23B 3.3 0x0A0D0C9E
1.4 0x0A0D1704 2.4 0x0A0DF26D 3.4 0x0A0D0CEE
1.5 0x0A0D4E99 2.5 0x0A0DF2B3 3.5 0x0A0D0D16
1.6 0x0A0DC4FC 2.6 0x0A0DF2D1 3.5.3 0x0A0D0D17
2.7 0x0A0DF303 3.6 0x0A0D0D33
3.7 0x0A0D0D42
3.8 0x0A0D0D55修复代码就不贴了。