It is well known that hackers are interested in stock and the currency markets.
Using this insider information, the gang members entered in profitable trades on the stock exchange.
According to the researchers hackers used a virus called Corcow Trojan to accomplish their nefarious task.
Corcow trojan has reportedly infiltrated 250,000 computers worldwide and infected over 100 financial institutions.
The Moscow Exchange has said that its systems were not hacked in the incident.
source: www.techworm.net