The first few days after the new virus hit were difficult for the people who had been stockpiling antivirus software, but by the end of the day, most of the company’s customers had installed the software, and the vast majority of customers were running it.
The virus did not affect Microsoft Office, but it did impact Windows 8, and Windows Phone.
Microsoft’s chief financial officer and its chief information security officer, respectively, have said the company has not identified any customers who are facing data breaches because of the virus.
The company said it is working to identify the people affected.
But if the company doesn’t find the problem, it will have to re-evaluate the security of its own software and possibly even the software of its enterprise customers.
Microsoft, which has been testing the virus since early October, says it has been able to protect a small number of users.
But it’s been unable to prevent the virus from spreading outside the company, which makes it a serious concern.
“The virus is not in our control, so we don’t have any plans to remove the threat,” Microsoft said in a statement on Monday.
The new virus is a bit of a mixed bag, with some of its features, like the ability to run the virus on the machines of Windows 8 and Windows 10 users, working.
But some of the more sophisticated features, such as a new “cognitive firewall” to prevent malware from running on infected machines, don’t work, and are potentially dangerous.
Some of the viruses can also be installed on machines that have no antivirus protection.
It’s not clear whether the new software will cause any damage to Microsoft’s businesses, though, since the company is only testing the program on its enterprise servers and has not been able or willing to make it available to businesses.
But Microsoft says it is looking into the possibility that the virus could infect other Microsoft systems.
It said that, since November 1, the virus has infected about 15 percent of Microsoft’s Windows 10 computers, up from a low of about 5 percent in late October.
Microsoft said it will provide more details on the issue in coming weeks.
The Associated Press contributed to this report.