I did a test lightning transaction by sending 0.00001 btc to some exchange with using bitcoin core 0.16 (downloaded from bitcoin.org and installed to dedicated pc) and... it took the rest balance of my wallet which was sent to unknown address.

Here is the transaction: https://www.blockchain.com/btc/tx/5d6111094be588c180661cb2f0ee21a7de28a7dea8641cb9921b4aada3175dd5

As you can see there is 0.00001 btc sent to some exchange wallet and also 0.00948723 is sent to unknown address (exchange says it's not belongs to them).

What was the second transaction?

  • 1
    It should be change. What's the balance of your wallet before and after the transaction? Jul 25, 2018 at 11:23
  • 1
    before it was like 0.0095 btc, and after it was 0
    – Ariloum
    Jul 25, 2018 at 11:45
  • So is it possible that bitcoin.org were hacked and their wallet was compromised with ghost second transaction which stole all your rest balance when you do a tx?
    – Ariloum
    Jul 25, 2018 at 13:08
  • 1
    Unlikely situation.
    – Penquin
    Jul 25, 2018 at 14:24

2 Answers 2


The second output is most likely change being returned to your wallet. Just like when you use a $5 banknote to buy a $1 item. You get $4 back in change. You don't try to tear off 1/5th of the $5 banknote.

Unspent Transaction outputs (UTXOs) can't be half spent, you spend the whole UTXO and get change back.

  • 1
    I didn't see any change back on my wallet.
    – Ariloum
    Jul 25, 2018 at 11:44

Make sure you are using the latest wallet version.

Try re-indexing your block. Run your wallet with reindex option

bitcoin-qt -reindex

Its clearly a change that should return to your wallet in some time.

Here your stat -

Total Input     0.0095 BTC
Total Output    0.00949723 BTC
Fees    0.00000277 BTC
  • I'm using different online tracking sites to check the wallet status. So it's definitely not a local database problem. blockchain.com/btc/tx/… as you can see I did a transaction 0.00001 btc. BUT there is another transaction inside it which sends 0.00948723 to unknown address. And I received at endpoint only 0.00001. And the rest was disappeared to unknown.
    – Ariloum
    Jul 25, 2018 at 12:47

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