Feeds

OK, we get the message, Microsoft: Windows Defender splats 1000s of WinXP, Server 2k3 PCs

Anti-malware update gaffe trashes axed OSes

Choosing a cloud hosting partner with confidence

Microsoft has fixed a snafu with Windows Defender that took down thousands of business PCs and servers running Windows XP and Server 2003.

The software giant responded to sysadmins complaining on TechNet that large numbers of their machines were borked after they’d installed Microsoft’s latest set of antivirus definitions.

Once the dodgy signature update for System Center Endpoint Protection (SCEP) and Forefront Endpoint Protection (FEP) had been installed, it caused PCs and servers to hang at logon until Msmpeng.exe, a core part of Windows Defender, crashed.

The only solution to getting affected machines back up was to uninstall the updated signatures.

One sysadmin took to TechNet to complain of 750 knackered PCs, with another claiming he'd seen 3,500 PCs walloped.

The culprit is a group of antivirus definition updates in SCEP and FEP, released on April 16. The versions most complained about were numbers 1.171.1.0, 171.46.0 and 1.171.39.0.

Redmond told The Reg that applying the latest set of antivirus signatures would rescue affected systems without the need to uninstall the update that caused the problems.

One Reg reader contacted us to say: “Seems like an engine and/or signature update to FEP in combination with a specific setting within FEP crashes FEP, which then knocks out the affected computer from the network.”

A Microsoft spokesperson admitted the company had released an anti-malware engine update that “may have caused interrupted service for customers” using the company’s security products.

The spokesperson said the latest signature update would automatically resolve the issue, implying there’s no need to uninstall the faulty signatures.

“Customers who have developed the most recent signatures do not need to take an action,” the spokesperson said.

Such problems are critical because security products like SCEP and Forefront are now Microsoft’s first and last line of defence for users against malware writers since Microsoft axed all support for Windows XP, and stopped releasing security patches for the ageing operating system, on April 8 this year. Windows Server 2003 remains supported until 14 July, 2015.

The advice for those still running Windows XP and Windows Server 2003 is to apply all the latest anti-virus patches and signatures to systems to try and stay safe. ®

Thanks to Reg reader Nik for the tip.

Remote control for virtualized desktops

More from The Register

next story
Download alert: Nearly ALL top 100 Android, iOS paid apps hacked
Attack of the Clones? Yeah, but much, much scarier – report
You stupid BRICK! PCs running Avast AV can't handle Windows fixes
Fix issued, fingers pointed, forums in flames
Microsoft: Your Linux Docker containers are now OURS to command
New tool lets admins wrangle Linux apps from Windows
Facebook, working on Facebook at Work, works on Facebook. At Work
You don't want your cat or drunk pics at the office
Soz, web devs: Google snatches its Wallet off the table
Killing off web service in 3 months... but app-happy bonkers are fine
First in line to order a Nexus 6? AT&T has a BRICK for you
Black Screen of Death plagues early Google-mobe batch
prev story

Whitepapers

Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
Getting started with customer-focused identity management
Learn why identity is a fundamental requirement to digital growth, and how without it there is no way to identify and engage customers in a meaningful way.
Driving business with continuous operational intelligence
Introducing an innovative approach offered by ExtraHop for producing continuous operational intelligence.
5 critical considerations for enterprise cloud backup
Key considerations when evaluating cloud backup solutions to ensure adequate protection security and availability of enterprise data.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?