Flaws in Microsoft's Internet Information Servers have been blamed for the hack attack on the Nasdaq and American Stock Exchange Web site last week. The weaknesses allowed hackers to breach security and trash one of the most high profile Web sites in the US. The allegation was made by London-based mi2g software which carried out a post mortem of the hack attack. "Initial analysis suggests that well publicised vulnerabilities in Microsoft's Internet Information Server have been exploited," said the report. "Whilst Microsoft has been regularly issuing software patches for holes found, there is no guarantee that all patches may have been applied by the network administrators," it said. The attack -- which left graffiti all over the walls of the financial Web site -- was allegedly carried out by the hacker group "United Loan Gunmen" (ULG). The most sensitive aspect of the attack is a claim by the ULG that it set up an email account on Nasdaq's computers. If this proves to be true, it would mean that ULG obtained "deep access" to the Nasdaq computer system severely compromising the security of the site. "On-line financial institutions, bourses and shopping sites ought to be aware that they need to put Internet security at the top of the board agenda," warned DK Matai, MD of mi2g software. Despite being contacted on Friday to discuss the matter, no one from Microsoft was available for comment by press time. ®