More about the Cryptopia hack:
https://elementus.io/blog/cryptopia-hack-transparency/"All times below are Eastern Time (GMT-5).
Sunday 13-Jan, 8:28am: Funds begin moving out of Cryptopia's two core hot wallets, one holding ether and the other holding tokens.
Sunday 13-Jan, 11:58pm: With the core wallets empty, residual quantities of funds begin leaving Cryptopia's 76k+ secondary wallets, a process that would continue for several days.
Monday 14-Jan, 6:00am: Cryptopia suspends trading, announcing they are undergoing unscheduled maintenance.
Tuesday 15-Jan, 3:00am: Cryptopia discloses the security breach and New Zealand law enforcement steps in.
Thursday 17-Jan, 5:58am: The last of Cryptopia's funds are drained.
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How much have the thieves attempted to cash-out at exchanges?...
Of the $16m that was stolen, the vast majority (~$15m) remains in two wallets controlled by the thieves:
0x9007a0421145b06a0345d55a8c0f0327f62a2224
0xaa923cd02364bb8a4c3d6f894178d2e12231655c)
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The hack continued for days after Cryptopia discovered the breach.
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After Cryptopia discovered the hack, they watched the funds continue to flow out of their wallets for four more days, seemingly powerless to stop it. As these wallets were not smart contracts, there should have been no technical complications preventing Cryptopia from securing the funds.
The only plausible explanation for Cryptopia's inaction is that they no longer had access to their own wallets.
It seems Cryptopia not only lost their funds, they also lost access to all, or nearly all, of their 76k+ Ethereum wallets.
One possible explanation is that Cryptopia had their private keys stored in a single server with no redundancy. If the thieves managed to gain access to this server, they could have downloaded the private keys before wiping them from the server, leaving Cryptopia unable to access their own wallets.
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2,000 Ethereum wallets and $46k in Ether remain at risk.
We count about 2,000 remaining Cryptopia wallets holding a combined balance of ~380 ETH (about $46k). Most of these funds were deposited by Cryptopia users after the initial hack took place, apparently unaware of the security breach."