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def decrypt(func): | |
""" | |
Decryption of zeus strings | |
""" | |
ZBOT_INDEX_MIN = 0x0 | |
ZBOT_INDEX_MAX = 0xe7 | |
data = {} | |
for i in range(ZBOT_INDEX_MIN, ZBOT_INDEX_MAX): | |
buf = Appcall.buffer("\x00" * 512) | |
# Call the Zbot function | |
func(i, buf) | |
data[i] = buf.value.decode("utf-16").rstrip('\x00\x00') | |
return data | |
def comment(data, func_name): | |
for xref in XrefsTo(LocByName(func_name)): | |
# Get previous instruction | |
ea = PrevHead(xref.frm) | |
# Check for mnemonics | |
if GetMnem(ea) == "mov": | |
# Get index value | |
op = GetOperandValue(ea,1) | |
elif "pop" in [GetMnem(ea), GetMnem(PrevHead(ea))]: | |
#search for a 'push 0xINDEX' | |
while True: | |
ea = PrevHead(ea) | |
if GetMnem(ea) == "push": | |
# Get index value | |
op = GetOperandValue(ea,0) | |
break | |
else: | |
continue | |
try: | |
# Add comments | |
MakeComm(ea, "index[0x{:X}] : '{:s}'".format(op, data[op])) | |
except: | |
continue | |
# Initialization ------------------------------------------ | |
FUNC_NAME = "decrypt_data_wide" | |
PROTO = "void __usercall {:s}(int data_index@<eax>, void *buf@<esi>);".format(FUNC_NAME) | |
# Execution ----------------------------------------------- | |
decrypt_function = Appcall.proto(FUNC_NAME, PROTO) | |
comment(decrypt(decrypt_function), FUNC_NAME) |
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