Created
November 6, 2019 18:51
-
-
Save alexander-hanel/06a7a2bb45233907bfb126803cee51f6 to your computer and use it in GitHub Desktop.
IDAPython script for decoding strings in nemty
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import base64 | |
from Crypto.Cipher import ARC4 | |
def str_decrypt(enc_data): | |
key = 'fuckav\x00' | |
cipher = ARC4.new(key) | |
try: | |
enc_data = base64.b64decode(enc_data) | |
except: | |
return enc_data | |
return cipher.decrypt(enc_data) | |
for xref in CodeRefsTo(0x407395, 0): | |
args = idaapi.get_arg_addrs(xref) | |
if args: | |
arg_offset = args[0] | |
enc_offset = idc.get_operand_value(arg_offset, 0) | |
enc_data = idc.get_strlit_contents(enc_offset) | |
if enc_data: | |
dec_str = str_decrypt(enc_data) | |
idc.set_cmt(enc_offset, dec_str, 0) | |
print dec_str, hex(enc_offset)[:-1], hex(xref)[:-1], enc_data | |
Author
alexander-hanel
commented
Nov 11, 2019
import base64
import hashlib
import string
from Crypto.Cipher import ARC4
def str_decrypt(enc_data):
temp_key = b"sosorin :)"
key = hashlib.sha1(temp_key).digest()
cipher = ARC4.new(key[:-4])
try:
enc_data = base64.b64decode(enc_data)
except:
return enc_data
return cipher.decrypt(enc_data)
for xref in CodeRefsTo(0x4036E7, 0):
args = idaapi.get_arg_addrs(xref)
if args:
arg_offset = args[0]
enc_offset = idc.get_operand_value(arg_offset, 0)
enc_data = idc.get_strlit_contents(enc_offset)
if enc_data:
dec_str = str_decrypt(enc_data)
if enc_data != dec_str:
if all(chr(c) in string.printable for c in dec_str):
idc.set_cmt(enc_offset, dec_str.decode("ascii"), 0)
print(dec_str, hex(enc_offset), hex(xref), enc_data)
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment