Feeds

MS kernel patch skirts infected machines

Damage control bypasses pwned PCs

Next gen security for virtualised datacentres

Microsoft's latest batch of patches contains a kernel update designed not to install on machines infected with a rootkit.

The move is designed to prevent the confusion that occurred when one of the patches released in February resulted in a Blue Screen of Death and continuous reboot cycles on some Windows XP machines.

Microsoft copped a fair bit of criticism for the incident before the cause was pinned down to the interaction between the hard-to-detect Tdss rootkit and a Windows kernel security update. Rootkits are a type of malware that attempt to avoid detection by anti-virus scanners by burying themselves in the likes of Windows kernel code.

Redmond's April patch batch also contains a Windows kernel patch. In an effort to prevent the same snafu as February, Microsoft is using technology designed to prevent the update from installing onto malware-compromised machines.

"This security update includes package-detection logic that prevents the installation of the security update if certain abnormal conditions exist" Microsoft explains in the FAQ for its MS10-21 patch.

"These abnormal conditions on a system could be the result of an infection with a computer virus that modifies some operating system files, which renders the infected computer incompatible with the kernel update."

The same technology was used in a modified version of the MS10-15 update, which was initially released as part of February's Patch Tuesday and revised with an "avoid infected systems" add-on in mid-March.

Users who attempt to install either the revised MS010-15 package or the new Ms10-021 kernel update on infected machines ought to get an error code.

Possible error codes (such as 0x8007F0F4) fail to explain what might have gone wrong, but a bit of judicious searching ought to direct sys admins or regular users who hit the snag to this advisory here. This notice explains that users who run across problems installing the patch are probably dealing with a malware-infected machine.

Microsoft's April patch batch included 11 bulletins along with an update to the software giant's Malicious Software Removal Tool. The idea is that this tool will remove malware and clean up systems which can then by safely patched at the second time of asking. ®

The essential guide to IT transformation

More from The Register

next story
Goog says patch⁵⁰ your Chrome
64-bit browser loads cat vids FIFTEEN PERCENT faster!
Chinese hackers spied on investigators of Flight MH370 - report
Classified data on flight's disappearance pinched
NIST to sysadmins: clean up your SSH mess
Too many keys, too badly managed
Scratched PC-dispatch patch patched, hatched in batch rematch
Windows security update fixed after triggering blue screens (and screams) of death
Researchers camouflage haxxor traps with fake application traffic
Honeypots sweetened to resemble actual workloads, complete with 'secure' logins
Attack flogged through shiny-clicky social media buttons
66,000 users popped by malicious Flash fudging add-on
prev story

Whitepapers

Top 10 endpoint backup mistakes
Avoid the ten endpoint backup mistakes to ensure that your critical corporate data is protected and end user productivity is improved.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Backing up distributed data
Eliminating the redundant use of bandwidth and storage capacity and application consolidation in the modern data center.
The essential guide to IT transformation
ServiceNow discusses three IT transformations that can help CIOs automate IT services to transform IT and the enterprise
Next gen security for virtualised datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.