The group, which calls itself the "United Loan Gunmen," posted an obviously false story on the site for a short amount of time under the headline, "United Loan Gunmen take control of Nasdaq stock market."
Despite claims in the story that the cybergang had "uprooted" the Web site, the only effects of the intrusion seemed to be defacing of the home page.
The Nasdaq site offers financial news and quotes.
Up just a few minutes
The phony page stayed up only a few minutes before Nasdaq's Web servers automatically detected and removed it, said B. K. DeLong, a staff member with security Web site Attrition.org. Reports of the defacement initially appeared on Attrition.org, which obtained a screenshot of the modified site before Nasdaq's automatic measures cut in.
Nasdaq officials could not confirm the intrusion at press time.
"Our sites are working perfectly," said Scott Peterson, a spokesman for Nasdaq. "We have no evidence of intrusion at this time. However, we take all such allegations very seriously and we are investigating at this time."
The United Loan Gunmen is a new group that has made a name for itself in recent weeks by defacing major sites, and leaking word of the defacements to Attrition.org. The same group has claimed responsibility for hacks on sites including ABC.com, C-SPAN and -- just this last Monday -- the Drudge Report.
More details to follow.