Microsoft has released on patch day (April 11, 2017) also a new version of Windows Malicious Removal Tool (MRT) as update KB890830. It seems that this update is causing serious issues.
Malicious Removal Tool (MRT) is shipped on each patch day to run once and clean systems from malware. On patch day (April 11, 2017) a new version of Malicious Removal Tool (MRT) has been released as update KB890830. I received yesterday some comments within my German blog, indicating trouble with update KB890830.
Update KB890830 blocks other updates
Last night I received also some e-mails from ‘another source’ (thanks Leon – but sometimes I have to take a nap ) reporting issues with update KBb4015550.
I’ve installed update kb4015550 on another pc and received an mrt.exe – error 0xc0000005,
I’ve translated the text, because it was written in a foreign language. Update KB4015550 is causing a MRT error 0xc0000005 (Access Violation) during install. MRT obvioudly blocks installing other updates. Leon wrote within a 2nd that he had analyzed other updates (KB890830 and KB4014983) as a source of install conflicts, but at least he found the root cause. He wrote:
I found the cause for mrt.exe error – it was caused by update kb 890830. The odd thing is, that I only use windows defender on my machines.
It seems, that MRT is causing serious trouble. My proposal: Hide update KB890830 in Windows 7/8.1 – and if MRT is already installed, uninstall KB890830 and block this update.
MRT collides with other AV software
Leon pointed out, that update KB890830 is causing also trouble with third party antivirus software. Here are a few links pointing to forum entries with related discussion.
Unable to update windows malicious tool (KB890830) (Norton Forum)
Is Microsoft Windows Malicious Software Removal Tool (KB890830) harmful…
Microsoft Update KB890830 won’t be installed unless Avast is turned off
Something went terrible wrong with MRT update this month. Are you also facing trouble with KB890830?
Addendum: A solution
Leon provided me with a fix: Just delete the mrt file in Windows\system32\mrt. The launch Windows Update and hide the April 2016 MRT update. Afterward, restart Windows Update search 3 times again, the updates KB890830 for January, February and March are offered. Let em install – so mrt will work in those older versions.