Microsoft will start feeding users an update to the critical Windows Update service in the next few days, several security experts said today.
Windows Update (WU) provides security patches and other fixes to Windows PCs. The service is accessed directly by consumers, and through the Windows Server Update Services (WSUS) component by enterprises.
The update was triggered by the discovery that Flame, a sophisticated, nation state-grade cyber espionage tool, had subverted WU to infect additional PCs within an already-penetrated network. The team behind Flame, which shared code with the makers of the even-better-known Stuxnet worm that sabotaged Iran's nuclear program, pulled off that first-of-its-kind hack by stealing digital certificates from Microsoft.
A week ago, Microsoft announced it would issue an update to WU to prevent copy-cats from duplicating Flame's feat. At the time, it said it would begin serving that update before the end of the week.
Microsoft did, in fact, push the update to some users last week, although it limited the scope of that audience, said researchers.
"It's done and tested, and as we understand it, has been offered to some users," said Wolfgang Kandek, chief technology officer at Qualys, in an interview.
Jason Miller, manager of research and development at VMware, said that he had heard from users who had received the new Windows Update client, and like Kandek, said Microsoft would unthrottle the update -- in other words, begin pushing it to all, or at least more, users -- "in a few days."
Microsoft also heeded calls to wait until after yesterday's Patch Tuesday to refresh WU by pausing the update, limited though it was, until users' PCs began downloading fixes for the 26 flaws the company delivered this month.
Several researchers, including Kandek and Andrew Storms, director of security operations at nCircle Security, said they had emailed contacts at Microsoft urging the company to wait.
"They released the WSUS update Friday, and started the WU update, but not everyone got it," said Kandek. "Then they put a pause on WU."
Last week, Storms had hoped Microsoft would do the smart thing, and delay the WU update until after Patch Tuesday, noting that to do different might delay some businesses deployment of the fixes.