At least 10 hacking groups using Microsoft software flaw FILE PHOTO: A Microsoft logo is seen in Los Angeles, California U.S. November 7, 2017. REUTERS/Lucy Nicholson (REUTERS)Premium . Updated: 11 Mar 2021, 10:34 AM IST Reuters The breadth of the exploitation adds to the urgency of the warnings being issued by authorities in the United States and Europe about the weaknesses found in Microsoft's Exchange software Share Via Read Full Story WASHINGTON : At least 10 different hacking groups are using recently discovered flaws in Microsoft Corp's mail server software to break in to targets around the world, cybersecurity company ESET said in a blog post on Wednesday.