Between 2006 and 2007, there was an almost threefold rise in Microsoft flaws, Qualys said on Wednesday.
"We have seen a huge jump in the vulnerabilities in Microsoft Office products," said Amol Sawate, manager of Qualys' vulnerability-management lab. "These charts show growth of nearly 300 percent from 2006 to 2007, primarily in that can easily be exploited by getting unsuspecting users to open Excel files sent via e-mail and instant message."Alan Paller, director of research for the Sans Institute, a computer-security training organization, said that the reason more were being found was that it was becoming increasingly profitable for crooks to target the software.
"It isn't that Microsoft isn'tb," Paller said. "The reason (is that) it is so lucrative to find vulnerabilities in Excel and Word, so there are a lot of (hackers) searching for them."
Microsoft declined to comment for this story.
Tom Espiner of ZDNet UK reported from London. CNET News.com's Ina Fried contributed to this report from San Francisco.