South Korea is a leader in ethereum cryptocurrency. Approximately 20 percent of global "ether" trades are exchanged for won, the South Korean currency. However, ether's popularity appears to have attracted those willing to exploit it.

Ethereumis a decentralized platform that runs smart contracts: applications that run exactly as programmed without any possibility of downtime, censorship, fraud or third party interference.

Ethereum currency is a digital currency, similar to Bitcoin, that can be used to pay for items.

Recently, customer information worth millions of dollars was stolen from South Korea's largest exchange, Bithumb, where customers buy and sell ether as well as Bitcoin.

Bithumb is the fourth largest cryctocurrencty exchange in the world by volume.

World's Fourth Largest Cryptocurrency Exchange Hacked, People Lost Tons Of Bitcoin And Ethereum https://t.co/IniAzxfcnF #bitcoin #crypto #… — Bitcoin Mad (@BitcoinMad) 5 July 2017

​Local news reports said that Bithumb contacted the South Korea cybercrime watchdog on June 30 after learning of the hack. According to reports a Bithumb employee's home computer was hacked and information on 30,000 customers was stolen.

No passwords were compromised, but reports suggest that South Korean officials are now investigating the hack.

If had indeed been stolen from Bithumb customers, this hack is just another reason why some argue that it may not be wise to entrust your funds to a third party.

In April 2017, a smaller South Korean cryptocurrency exchange was hacked and lost millions of dollars.

Other options besides storing funds with a third party for ethereum users include storing the private keys that control their funds on hard drives that are not connected to the internet. This isn't as convenient (or maybe even beneficial, if you're a day trader), but gives hackers fewer openings.

According to sources, this may be just the start of things to come. As ethereum and cryptocurrencies in general continue to rise in value and gain mainstream attention, more hackers will most definitely come along and try to take advantage.