Largest Bitcoin exchange reports heavy DDoS attack

The world’s largest exchange of the digital Bitcoin currency is back online after reporting a “stronger than usual DDoS” attack

The world’s largest exchange of the digital Bitcoin currency is back online after reporting a “stronger than usual DDoS” attack just two hours into resumed trade after a lengthy suspension.

The value of the digital currency has been unstable after over a week of disruptions at the main MTGox exchange, which handles about 80% of trades in Bitcoins.

Last week the value of the digital currency was hit by delayed trades due to a combination of distributed denial-of service (DDoS) attacks and high trading volumes.

This week MTGox imposed a 12-hour halt in trading to upgrade its servers to handle the increased demand, but went offline shortly after resuming trade due to another DDoS attack.

US reports quote an MTGox representative as saying the exchange comes under DDoS attacks every day. Last week, MTGox speculated the attacks were aimed at manipulating the value of the digital currency.

The exchange has admitted it does not know who is behind the attacks, but has vowed to find a way to beat the assaults and said it would handle all pending trades and waive fees for 48 hours.

The disruptions this week have sent Bitcoin hurtling downwards from a high of $266 on Wednesday to a low of $65 when it called the 12-hour halt. According to MTGox, trades were at $95.9 early Friday.

The digital currency has been growing in popularity with investors, but it has been a frequent target for criminal activity, including thefts, hacks and scams, with nearly a quarter of a million dollars stolen in a virtual heist last year.

DDoS attacks have been common for 20 years and typically flood the intended target with large amounts of network traffic in an attempt to render it unreachable in a “brute force” attack.

 Attacks of this nature are generally used to extort money from targeted organisations or as a weapon to disrupt organisations or companies. Techniques have been developed to mitigate against them.

However, information security researchers have discovered a new type of DDoS that is more difficult to detect and block because it adopts a “low and slow” approach.

Security firm Check Point told delegates at the CPX2013 customer and partner event in Barcelona this week that DDoS attacks are now being carried out by targeting specific apps. Some attacks have even targeted a single web form within an app.

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