The more technical explanation of what happened is found here.
A malicious element used the open-source/open-access Verge Currency code to create a secret side-chain. By reducing the difficulty of the mining, they were able to create what seemed like 6 months of new transactions.
Since Verge is a distributed currency, each full wallet is its own Node, they were able to use hashing power to push forward nodes with the wrong chain, causing the verge explorer to go down & making it seem like the chain had rolled back 6 months. Due to the sudden increase of network power, every Verge explorer automatically connected to the empty chain.
This new situation caused many transactions to show as pending (since the blockchain no longer had previous transaction id’s) due to the new chain having empty blocks.
At this point most exchanges and miners had halted their activity to prevent transactions from going on the wrong chain.
Some exchanges continued trading as they trade on off-chain trading, which is regulated by each exchange.
Once the team determined where the malicious chain began, we proceeded to push an earlier update with a a checkpoint to block out the malicious chain.
This is when we asked our community to download the new wallet.
Retaking our chain
Digital currencies are as strong as the network they run on. In plain English this means, the more people running the chain, the stronger it is.
To solve this attack, we encouraged everyone in our social media channels, to download and run the new wallet, and block all nodes connecting to the earlier one. Slowly isolating the bad chain.
This and cooperation with the largest group of verge miners made it possible to push our chain past the previous one.
As soon as this happened, the Verge Explorers, Miners and Exchanges were all able to connect to the correct chain again and account balances and pending transactions have been restored as if nothing happened.
A combination of factors made this attempted attack possible, but the strength of the XVG community and its blockchain overcame the attackers.
To prevent this again, we are working on a more permanent corrections.
Meanwhile, help the chain, download a QT wallet, and mine some Verge.