6 ms·
From the mt.gox site: Huge Bitcoin sell off due to a compromised account - rollback The bitcoin will be back to around 17.5$/BTC after we rollback all t
by buro9 15y ago
From the mt.gox site:
Huge Bitcoin sell off due to a compromised account - rollback
The bitcoin will be back to around 17.5$/BTC after we rollback all trades that have happened after the huge Bitcoin sale that happened on June 20th near 3:00am (JST).
Service should be back by June 20th 10:00am (JST, 01:00am GMT) with all the trades reversed and accounts available.
One account with a lot of coins was compromised and whoever stole it (using a HK based IP to login) first sold all the coins in there, to buy those again just after, and then tried to withdraw the coins. The $1000/day withdraw limit was active for this account and the hacker could only get out with $1000 worth of coins.
Apart from this no account was compromised, and nothing was lost. Due to the large impact this had on the Bitcoin market, we will rollback every trade which happened since the big sale, and ensure this account is secure before opening access again.
I'm interested in the fact that they can do a rollback... is that just a rollback of their transaction log? Are they buffering transactions for a significant period before submitting them back to the network?
- iki23 15y ago[Update - 2:06 GMT] What we know and what is being done. * It appears that someone who performs audits on our system and had read-only access to our database had their computer compromised. This allowed for someone to pull our database. The site was not compromised with a SQL injection as many are reporting, so in effect the site was not hacked. * Two months ago we migrated from MD5 hashing to freeBSD MD5 salted hashing. The unsalted user accounts in the wild are ones that haven't been accessed in over 2 months and are considered idle. Once we are back up we will have implemented SHA-512 multi-iteration salted hashing and all users will be required to update to a new strong password. * We have been working with Google to ensure any gmail accounts associated with Mt.Gox user accounts have been locked and need to be reverified. * Mt.Gox will continue to be offline as we continue our investigation, at this time we are pushing it to 8:00am GMT. * When Mt.Gox comes back online, we will be putting all users through a new security measure to authenticate the users. This will be a mix of matching the last IP address that accessed the account, verifying their email address, account name and old password. Users will then be prompted to enter in a new strong password. * Once Mt.Gox is back online, trades 218869~222470 will be reverted. https://support.mtgox.com/entries/20208066-huge-bitcoin-sell-off-due-to-a-compromised-account-rollback https://support.mtgox.com/entries/20208066-huge-bitcoin-sell...
- dekz 15y agoI for one certainly wouldn't be going back. [MD5] is enough to tell me they only half heartedly care about securing user data, no matter how many buzz words they throw in now.
- norswap 15y ago"We have been working with Google to ensure any gmail accounts associated with Mt.Gox user accounts have been locked and need to be reverified." Ah, that's why I had to change my password then.
- bermanoid 15y agoYes, I was also worried when I saw the suspicious activity flag had been tripped on my acct., but apparently that doesn't actually mean that anyone actually tried anything, just that our e-mails appeared in the list. Luckily I never reuse passwords for important stuff like e-mail or anything that touches money...
- rmc 15y agoThis allowed for someone to pull our database ... so in effect the site was not hacked. Weasel words. If someone has a dump of your database, then your site was hacked.
- lubos 15y agomtgox acts like a central authority. basically all these trades were happening in mysql database within the exchange between internal accounts, there were no actual bitcoin transactions.
- anigbrowl 15y agomtgox acts like a central authority Goodbye frying pan, hello fire.
- wmf 15y agoBut if you bought a bunch of BTC at $0.01 and then withdrew them, Mt.Gox should have irreversibly sent that over the real Bitcoin network.
- weavejester 15y agoIt sounds as if Mt. Gox managed to shut things down before anyone could do that.
- kristofferR 15y agoYeah, but my guess is that not many people managed to withdraw them because of the stability problems the site had/have. Mt.Gox will probably have some losses, but not that high I think.
- mehwoot 15y agoThis exactly. People _could_ have withdrawn a bunch, but mostly that didn't happen.
- lubos 15y agothere is daily limit though. you can only withdraw up to 80 BTC a day.
- jyu 15y agoWhat source are you getting this 80 BTC / day withdrawal limit from?
- weavejester 15y agoTrades are internal to Mt. Gox until you withdraw your money either as bitcoins or as USD. The compromised account had a $1000 per day withdraw limit, so the thief could only withdraw $1000 after selling all those coins. The rest of the cash is still within Mt. Gox, and therefore the state of the Mt. Gox DB can be rolled back to before all the coins were sold.
- lubos 15y agowhich makes me think mtgox got very lucky. I mean the hacker could overcome $1000 limit a day (roughly 80 bitcoins) by creating thousands of bogus accounts, putting on the market bid orders at $0.01 in all accounts, drive the market to the bottom like he did to fill his orders and quickly transfer 80 bitcoins from each account out of the exchange. he could get away with bitcoins worth of millions irreversibly and completely anonymously.
- weavejester 15y agoI think they were very lucky. Quite frankly I hope people take note of these near-misses and think a lot more about security.
- Kurtz79 15y agoIt wouldn't be even necessary. The 1000 USD is relative to the current price I suppose. So if I have access to an account with 500K bitcoins and I sell 400K bitcoins so that the price drops to 0.01 (like it did), and then I transfer the 100K bitcoin left in the account to my bitcoin address(and I can with the driven down exchange price) when the price goes back up I would have made a killing.
- mietek 15y agoAs I understand, there is also a 50 BTC withdrawal limit.
- waterlesscloud 15y agoOne would assume the $1000 limit is in the mtgox code. So if the hacker had full server access...
- sunchild 15y agoAnd who gets to decide which trades are rolled back? By what criteria?
- hollerith 15y agoIt is pretty clear that Mt Gox rolled back all trades from now to the first big unauthorized trade.
- rmc 15y agoSo if you had already done a legitimate trade it's gone? "Sorry you made some money there, but someone else got affect by something else, so we've undone that". So much for "There are no chargebacks on BitCoin"
- Flenser 15y agoWhen designing a system like this you have to have a veil of ignorance. There may from time to time be attacks or defects that mean some people lose a lot of money while others gain some. Not knowing which will happen to you, how would you want the system to work? http://en.wikipedia.org/wiki/Veil_of_ignorance http://en.wikipedia.org/wiki/Veil_of_ignorance
- mestudent 15y agoSo much for "There are no chargebacks on BitCoin" Well this is trading through an intermediary, you can't really expect it to work that way otherwise something like this would have a lot more incentive for wrongdoers. If you really want to have no chargebacks you have to go the harder route of one on one trading, with everything that comes along with that.
- Andys 15y agoAnd of course, one on one bitcoin trading is already alive and well at http://bitcoin-otc.com/ http://bitcoin-otc.com/
- 15y ago