In sample file, sub_401690 is decompress function. Here is script solve:

```
def decompress(data):
if len(data) < 4:
raise ValueError("Invalid data")
if data[0] == 1:
return data[4:]
out = bytearray()
i = 4
n = len(data)
while i < n:
if i + 1 >= n:
break
flag = data[i] | (data[i + 1] << 8)
i += 2
bits = 16
while bits > 0 and i < n:
if flag & 1:
if i + 1 >= n:
raise ValueError("Incomplete back-reference")
first = data[i]
length = (first & 0x0F) + 1
offset = ((first >> 4) << 8) | data[i + 1]
i += 2
if offset > len(out):
raise ValueError("Invalid offset")
src_index = len(out) - offset
for _ in range(length):
out.append(out[src_index])
src_index += 1
else:
out.append(data[i])
i += 1
flag >>= 1
bits -= 1
return bytes(out)

with open('data.bin', "rb") as f:
data = f.read()
decompressed = decompress(data)
with open('output', "wb") as f:
f.write(decompressed)
```