Bitcoin Forum

Hello,

Yesterday after upgrade, one of my wallets was emptied. 9btcs were lost. I have noticed that the number of transactions that were there before were reduced from 450 to 220 and that some of transactions we're doubled? The ones that went to satoshidice.

Wallet wasn't encrypted, I know were I went wrong, but I'm just wondering what happened? I'm willing to submit reports of double transactions.

Thanks beforehand.

The OS is Lion, and antivirus didn't report anything suspicious.

do a re-scan?

Nothing... ClamXav antv...

He means start the client with -rescan so it re-balances your account according to the block chain.

I have uploaded the wallet.dat to blockchain. It's empty.

do you have a older copy of your wallet? What OS are you on?

Yes, I do have an old wallet.dat, Lion Mac.

I understand that the unprotected wallet can be emptied, but how can the blockchain be manipulated?

Transaction detail popup says I sent btcs to 2 address in one transaction...

I would feel ok if I just saw that someone gained control over my unprotected wallet and sent btcs to another address, but how did he retroactively manipulated the blockchain history, and how can one transaction contain 2 recipients?

Is this a bug in blockchain? Anyone please?

One is a change address?

One address is the recipient, and the other is a "change address", to which to "change" is sent.

Hmmm, don't get it... Could you please elaborate?

How can someone reduce the number of transactions on my wallet?

Yesterday, there were 450 transactions and 9.16btc ballance, today after upgrade I have 250 transactions and 0.0001btc balance... The blockchain has been manipulated...

OK, that's a good sign.  I think your coins may still be there.  Don't panic.

Have you tried downloading the latest client (8.1) then running if from the command line like this: bitcoin-qt -datadir=/folder/with/wallet.dat -rescan

It will take a while, but do that first with your backed-up wallet, then with your regular one.

It would be unheard of for the blockchain to have been manipulated, and if that happened much larger accounts than yours would be affected.

EDIT: Just to be sure, where did you download your upgrade from?

When you send coins, they are sent to at least 2 different addresses. One is your intended recipient address. The other is a change address that you own. In some clients, the change address can be the same as your original public key address.

Also, your backup may be old. You need the latest one if you had done that many transactions.

Yes, totally, my bad.  If there are more than 100 transactions since you made your backup, you need to use the latest one.  

But the fact that this happened right around your upgrade makes me think that you've encountered a (very panic inducing) bug that can be resolved if you keep your cool.

Ok, thanks guys, I'll try first with rescan.

But shouldn't upload of wallet.dat to blockchain do the same as rescan?

Yes, theoretically.  But I'm not very familiar with blockchain.info  I'd download the very latest official bitcoin-qt client (8.1), not earlier versions since there was a change in database backends that could be causing your problem.  And then just >bitcoin-qt -datadir=/folder/with/wallet.dat -rescan  

First with your regular wallet, and if that doesn't work with your backup.  It will take a while but please let us know how it goes.

PS: Make sure your antivirus and/or firewall are not blocking bitcoin.

Yes, I will definitelly post result here. Thanks.

ok guys, rescan didn't work, yet it gave me an idea... I pulled the old bitcoin-qt version including wallet and chain files from 2 weeks ago using time machine...

balance looks ok and it's not infected with unknown transactions... since there are many transactions on that wallet and i think it is dating from early 2011, I will just forward funds to another one which is using latest bitcoin-qt and download the whole chain again... also, i had a hard drive accident in june 2011 and i changed the whole computer couple of months ago... it could be that just the crc during copying on backup caused the craziness on my piece of blockchain since it has changed a couple of hard drives in the last 2 years...

many thanks for assistance...

cheers

Well, you could spend money on bitcoin, and if you restored a backup from 2 weeks ago, and if bitcoin-qt hadn't yet caught up with the blockchain, it would still show your spent balance.  But you couldn't get any confirmations if you tried to spend them.  So this is not really a definitive restoration until the old client has caught up with the blockchain.  So make sure the client is caught up with the blockchain before you try to spend them (make sure it no longer says "unsynchronized").

Good luck.

If you still can't figure it out, you could try sending your wallet.dat file to a very trusted member here. Someone who has good reputation. They will see what they can from your file. Then they can send you back all (or almost all) of your bitcoins to your new wallet.

But try doing everything by yourself first.

Wallet is in sync now. Guess that's a good sign. Will try to do a test transaction.

How did it go?

so far so good, current status: sent with 3 confirmation...

Great, I'm glad.  For the reference of future readers, the fact that you were able to retrieve them using Mac TimeMachine means that if this approach hadn't worked, someone would likely have been able to guide you to get your Bitcoins through using something like pywallet to dump the keys.  So if you "loose" Bitcoins during an upgrade, they're almost certainly still there, and if you remain calm like marra you should be able to retrieve them.

In any case, glad you got your coins back marra.   Well done.

In the future, all of this will be easier...  Getting better by the day.

And the transfer is complete, 6 confirmations... :) woohooo, blockchain kept its integrity and I saved my BTC funds...

I propose to everyone to backup these 3 things before upgrading bitcoin-qt:

- wallet.dat
- a whole copy of last working blockchain
- previous working version of bitcoin-qt

Thanks for all the ideas guys, this makes me even more confident in the future of btc...

nice, i went though the same issue when i had to upgrade my wallet.. half my btc were confirmed and half werent.. a rescan fixed it.