Bitcoin exchange BitStamp is reporting yet another hacker attack. This time anonymous criminals are sending phishing e-mails.

The bitcoin exchange warned customers and users about the attack through Twitter:

The phishing letters emulate BitStamp’s corporate style. Hackers are asking users to submit their logins and passwords. Criminals are making use of recent BitStamp announcements: the phishing letters mention the recently lowered transaction fee. Nejc Kodric, CEO of BitStamp, announced a substantial reduction in the fees on March 3.

This is not the first attack against BitStamp this year. On the night of January 4–5, several users reported that they were unable to withdraw funds. Several hours later, BitStamp officially announced the suspension of all operations. Later in the day, managers of the exchange informed clients that it became a victim of a hacker attack. Nejc Kodrič assured users that their balances, as held before January 5, were safe.

On January 10, the company resumed operations and introduced additional security measures. The exchange’s servers were transferred from Lyublyana to San Francisco. BitStamp customers remained loyal to the trading platform. According to Coinography, on January 10 the exchange significantly increased its market share, with 7.8% of all exchange operations passing through BitStamp. Later this share decreased (while the share of the Chinese bitcoin exchange Huobu grew), but the effect of the suspension of trade on market share seems to have been negligible.

For all of BitStamp’s trouble, the attack affected not only loyal clients, but the bitcoin market as a whole. The price of the digital currency came close to $200. Bitcoin sceptics raised their voices against the digital currency and noted its volatility again. From January onwards, bitcoin enthusiasts and journalists mentioned BitStamp when talking about hacker attacks against any bitcoin exchange. Now BitStamp itself is under attack again