The Russian Trading System (RTS) was forced to cease trading for an hour on Thursday after being hit by a computer virus.
Three Russian markets — the FORTS derivatives market, the Classic, and the T+0 market — were closed from 1615 to 1720 MST, (1315-1420GMT) as a result.
"Trading on our exchange was halted for a while but the glitch was fixed pretty fast," RTS spokeswoman Larisa Gorbunova told ZDNet UK.
It's not clear which virus was to blame, but the RTS did reveal that it arrived over the Internet and attacked a computer connected to the trading testing system. "The infected computer started to generate tremendous amounts of false traffic, causing the RTS routers to overload," said Dmitry Shatsky, vice-president of the RTS, in a statement.
"As a result, the 'work' traffic — data being entered into the trading system — was not processed. RTS experts took a series of measures to prevent similar virus attacks in the future,” said Shatsky.
After the problem was localised, the infected computer was disconnected from the network. Exchange specialists checked all of the systems, rebooted, and recommenced operations after an hour.
"No irreparable damage to the RTS trading systems was done; timely intervention by the exchange experts prevented trading data from being lost," said RTS.
Gorbunova explained that RTS is carrying out an internal investigation, but could not say whether the police were involved.
It was "ironic that while people were worrying about Nyxem, a stock exchange was disrupted," said Graham Cluley, senior technology consultant for antivirus vendor Sophos.