bitcoin core did a transaction that i did not do!

[cuddaloreappu]

Yesterday as usual i checked my address balance with blockchain and found out half of it had gone to an address i haven't seen or know..but i restarted my core client and the balance was fully there..

then i sent all my coins to a new address and then transferred them back finally blockchain shows correct balance..

Can someone please tell me why blockchain.info showed a balance and a transaction which was not and did not happen?

[shorena]

Yesterday as usual i checked my address balance with blockchain and found out half of it had gone to an address i haven't seen or know..but i restarted my core client and the balance was fully there..

then i sent all my coins to a new address and then transferred them back finally blockchain shows correct balance..

Can someone please tell me why blockchain.info showed a balance and a transaction which was not and did not happen?

They had problems with their database in the past. I dont know what happened, but I suspect they have problems again. Blockchain.info is just one blockchain browser, its not the blockchain. You can also try e.g.
http://blockr.io/ or
http://blockexplorer.com/

If you suspect that your data might be compromised it would be wise to make a new wallet with a clean machine and transfer the coins there. Just to be safe. Or use a properly generated paper wallet.

[Lamigo]

Yesterday as usual i checked my address balance with blockchain and found out half of it had gone to an address i haven't seen or know..but i restarted my core client and the balance was fully there..

then i sent all my coins to a new address and then transferred them back finally blockchain shows correct balance..

Can someone please tell me why blockchain.info showed a balance and a transaction which was not and did not happen?

The whole incident sounds like a confusion on the use of "change address".

Bitcoin Core uses a new change address to handle "change" every time, and the change addresses were hidden from your list of receiving addresses.

[burekzastonj]

can you provide more data, like tx id or addy or whatever relevant ?