Attempts Made to Block Access to NASDAQ OMX Sites

Nasdaq OMX Group Inc. (NASDAQ:NDAQ) confirmed that it experienced "intermittent service disruptions" to its websites on Tuesday; however, there is no indication that security was breached and it did not affect trading systems, according to reports.

"During the past 24 hours, Nasdaq OMX has experienced intermittent service disruptions on our corporate websites," a Nasdaq spokesman told Dow Jones in a statement. "We are working with our Internet service providers to resolve these issues."

The outage impacted the corporate site for Nasdaq OMX, as well as the main portal for trader communications, this morning at about 10:45 ET, the newswire reported.

This is not the first time a major exchange operator’s website was the target of a cyberattack. Last year, Nasdaq OMX experienced a security breach to a site used by corporate board members to share company documents. The New York Stock Exchange has also experienced “denial of service” attacks in the past .