Coinbase "(PHONE)" Number ®+1-(855::519+.3027) | Coinbase
 

Coinbase "(PHONE)" Number A full blockchain analysis is beyond the scope of this article. Further research into the addresses sending the double spend transactions, the history of sends/receives from the addresses, the block fields such as timestamp, and the subsequent movement of miner rewards from attack blocks may shed light on the threat actor or actors behind these attacks.
We observed the following deep chain reorgs:
Common ancestor: 7245623. Depth 4 / Length 7. No double spends were observed in this reorg. We noted that this was a reorg of unusual depth for ETC.
Common ancestor: 7248488. Depth 5 / Length 6. No double spends were observed in this reorg. We noted that a second reorg of unusual depth was highly suspicious, but did not necessary indicate an attack as there was no double spend and the depth was still below the ETC confirmation limit for most services.
Common ancestor: 7249343. Depth 57 / Length 74. A transaction of value 600 ETC in orphaned block 7249357 was double spent by a transaction in attacker block 7249361**.
We ceased interacting with the ETC blockchain upon observing this reorg. Coinbase was not the target of this double spend and no funds were lost.
Common ancestor: 7254419. Depth 32 / Length 53. A transaction of value 4,000 ETC in orphaned block 7254430 was double spent by a transaction in attacker block 7254435**
Common ancestor: 7254568. Depth 123 / Length 140. A transaction of value 5,000 ETC in orphaned block 7254646 was double spent by a transaction in attacker block 7254656**
Common ancestor: 7255033. Depth 60 / Length 79. A transaction of value 9,000 ETC in orphaned block 7255055 was double spent by a transaction in attacker block 7255066*
Common ancestor: 7255204. Depth 25 / Length 35. A transaction of value 9,000 ETC in orphaned block 7255212 was double spent by a transaction in attacker block 7255225**.
Common ancestor: 7255476. Depth 37 / Length 46. A transaction of value 15,700 ETC in orphaned block 7255487 was double spent by a transaction in attacker block 7255492**.
Common ancestor: 7255542. Depth 67 / Length 85. A transaction of value 15,700 ETC in orphaned block 7255554 was double spent by a transaction in attacker block 7255563**.
Common ancestor: 7255662. Depth 62 / Length 110. A transaction of value 24,500 ETC in orphaned block 7255669 was double spent by a transaction in attacker block 7255681**.
Common ancestor: 7255998. Depth 69 / Length 86. A transaction of value 5,000 ETC in orphaned block 7256012 was double spent by a transaction in attacker block 7256022**.
Updates as of 10:27pm PT, January 7
Common ancestor: 7261497. Depth 44 / Length 54. A transaction of value 26,000 ETC in orphaned block 7261492 was double spent by a transaction in attacker block 7261497**.
Common ancestor: 7261603. Depth 35 / Length 44. A transaction of value 52,800 ETC in orphaned block 7261610 was double spent by a transaction in attacker block 7261614**.
Common ancestor: 7261647. Depth 8 / Length 9. No double spends were observed in this reorg.
Common ancestor: 7261676. Depth 37 / Length 47. A transaction of value 52,200 ETC in orphaned block 7261684 was double spent by a transaction in attacker block 7261690**.
Next Steps
The Coinbase team is currently evaluating the safety of re-enabling sends and receives of Ethereum Classic and will communicate to our customers what to expect regarding support for ETC. Coinbase takes security very seriously. As part of that commitment, we monitor blockchains for activity that could be harmful to our customers and take prompt action to safeguard funds. We want to emphasize to customers that Coinbase strives to be the most trusted and safest place to buy, sell, or store cryptocurrency.
* It is actually the chain with the most accumulated work, rather than the chain with the most blocks, that defines the canonical history. In most cases, these chains will be the same