We have received a report that concerns anybody who frequently visits the BitcoinTalk forums, and has updated one of their coin clients as of late. A user by the name of “diabanhxeo” has been spreading hacked cryptocurrency clients for various coins, containing a backdoor in order to steal wallet.dat files.
The report was brought to our attention by the Opalcoin team, as they had noticed there was a hacked/misbehaving client on the network. It turns out one of the Bitcointalk forum users has been spreading an infected client; not just for OPAL, but also for different altcoins which have seen wallet updates as of late.
These hacked clients contain a backdoor, giving that user access to any computer where these malicious clients are installed. As a result, he/she will then breach your computer and attempt to steal any of your wallet.dat files. The wallet.dat file contains your coin balance and transaction history, so your coins could be gone before you know it.
Fake downloads are rather easy to spot though, as the download links are usually embedded in a reply, and not posted by the official coin developers or team members. It also appears this user targeting Windows users specifically, and uses RAR files to package the malicious client, whereas coin developers usually use ZIP files.
As a result of a malicious Opalcoin being spread, the developer team has decided to initiate a rollback of the blockchain. This is not the first time we see an altcoin take this route, as Vericoin has done exactly the same a few months ago, albeit because of a different reason.
All of the exchanges will be compensated by the OPAL team in order to repay the lost Bitcoin. However, it is up to the OPAL community whether this rollback will actually take place or not. You can cast your vote by reading the following Google Doc :
Users have to take the following into consideration should this rollback occur :
If you lost coins due to the malicious attack, you will be refunded
Any OPAL purchase with Bitcoin during this period will grant you a BTC refund.
While we are still waiting on an official figure, it seems the total amount of OPAL affected by this hack could be as high as 2.5 million. If you do some quick calculations, that is nearly 17% of the entire OPAL coin supply.