Confused about this particular Multisig transaction with a (maybe) invalid scripts, but spent output

Question

I am confused about this particular transaction:

{
  "txid": "c49b3c445c89d832289de0fd3b0281efdcce418333dacd028061e8de9f0a6f10",
  "hash": "c49b3c445c89d832289de0fd3b0281efdcce418333dacd028061e8de9f0a6f10",
  "size": 450,
  "vsize": 450,
  "version": 1,
  "locktime": 0,
  "vin": [
    {
      "txid": "417fa57fba175e30300b1a217077364e1b5d84df5fd72967e7edc0497419b3db",
      "vout": 1,
      "scriptSig": {
        "asm": "3045022100b6db6e71652d2dcaa818c24d7dcba0ddca9a9a09f45a5a8b175784dde494d78602204e4b1042564da546b032f09eb02d2211f9e8fa3aeb3c987a28962a0a7a6d312b[ALL] 037a380cf3628417c275e9010eea2d7b2a05337d38af25054675e3441a43aa4565",
        "hex": "483045022100b6db6e71652d2dcaa818c24d7dcba0ddca9a9a09f45a5a8b175784dde494d78602204e4b1042564da546b032f09eb02d2211f9e8fa3aeb3c987a28962a0a7a6d312b0121037a380cf3628417c275e9010eea2d7b2a05337d38af25054675e3441a43aa4565"
      },
      "sequence": 4294967295
    }
  ],
  "vout": [
    {
      "value": 0.00900000,
      "n": 0,
      "scriptPubKey": {
        "asm": "1 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff 02323c909b017748294c1d1fb82648b2c2905cd941d9a863e036b3157e8aa85dd3 3 OP_CHECKMULTISIG",
        "hex": "514c78ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff4c78ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff2102323c909b017748294c1d1fb82648b2c2905cd941d9a863e036b3157e8aa85dd353ae",
        "type": "nonstandard"
      }
    }
  ]
}

It seems like the output script is invalid and it contains no output addresses.
Doing a scriptdecode yields:

{
  "asm": "1 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff 02323c909b017748294c1d1fb82648b2c2905cd941d9a863e036b3157e8aa85dd3 3 OP_CHECKMULTISIG",
  "type": "nonstandard",
  "p2sh": "3Pr9qaUxaHFZbbdojAZFozH34dEqjpe4dU"
}

which normally would be fine, invalid script, value burnt - no problem
However, this output is spent here:

{
  "txid": "f1200ee994dbca0213e3cfab0a2c35eb694e0f3f1eb50090cd84090aa10d8a17",
  "hash": "f1200ee994dbca0213e3cfab0a2c35eb694e0f3f1eb50090cd84090aa10d8a17",
  "size": 160,
  "vsize": 160,
  "version": 1,
  "locktime": 0,
  "vin": [
    {
      "txid": "c49b3c445c89d832289de0fd3b0281efdcce418333dacd028061e8de9f0a6f10",
      "vout": 0,
      "scriptSig": {
        "asm": "0 30460221008bcf597d5d6a7b2ccf3913983a2d978953e745fa6431331539ded8dc5cbd9f1402210093a4375f9d880fe506e3abcec15a919718e5946b21f823c6d35b539a2386b827[ALL]",
        "hex": "004930460221008bcf597d5d6a7b2ccf3913983a2d978953e745fa6431331539ded8dc5cbd9f1402210093a4375f9d880fe506e3abcec15a919718e5946b21f823c6d35b539a2386b82701"
      },
      "sequence": 4294967295
    }
  ],
  "vout": [
    {
      "value": 0.00800000,
      "n": 0,
      "scriptPubKey": {
        "asm": "OP_DUP OP_HASH160 c676ea066cc2a6b41b0ace8e287fd38030f0b97c OP_EQUALVERIFY OP_CHECKSIG",
        "hex": "76a914c676ea066cc2a6b41b0ace8e287fd38030f0b97c88ac",
        "reqSigs": 1,
        "type": "pubkeyhash",
        "addresses": [
          "1K6PFHRVyehbAd1GAboiJBfUToUv5f9fQv"
        ]
      }
    }
  ]
}

What was the signature used? What is the address that signed for this?

Answer 1

The script is valid, I was assuming that bitcoin core would be the authority.
Script decode:

51  OP_1
4c  Push data
78  Push 120 decimal  = 78 hex bytes
    ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
4c  Push data
78  Push 120 decimal  = 78 hex bytes
    fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
21  Push 33 dec = 21 hex: 
    02323c909b017748294c1d1fb82648b2c2905cd941d9a863e036b3157e8aa85dd3
53  OP_3
ae  OP_CHECKMULTISIG

02323c909b017748294c1d1fb82648b2c2905cd941d9a863e036b3157e8aa85dd3
translates to this base58 address:
1AqLAdfMzfVpdCAtk4rMCUCK6vvNUkGBdm
that can sign for the transaction: