• Microsoft tries to fix the sfc /scannow bug introduced by a patch in July, ends up clobbering Defender Malware

    @DrBonzo reports here on AskWoody:

    I’m running Win 7 Pro, SP1, x64. I just updated (actually about an hour ago by now) the definitions in MS Security Essentials to 1.301.1608.0. I tried a Full Scan and it quit scanning after 29 files. Tried a Quick Scan and it also stopped after 29 files. It’s not throwing any error codes and says that no threats were found after scanning 29 files. Gives me the big green checkmark. So, it looks just like a normal Full Scan except it only scans 29 files.

    I shut down the computer, restarted and attempted another definition update but was told I was already up to date. Tried another Full Scan with the same results as above.

    I’m now seeing reports from all over.

    Günter Born published an explanation in German (translated by Google):

    Earlier this week, Microsoft announced a silent update of the Defender Antimalware engine to version 4.18.1908.7. The update was long expected by me to fix the issue in the System File Checker caused by July 2019 updates…

    Microsoft has smuggled a friendly bug on the system. If you open up Windows security and have the system checked with a quick scan, after a few seconds and five files is over.

    Looks like the problem’s widespread. The solution? Roll back the silent update!

    There’s a reason why I’m not optimistic that MS has fixed its patching problems.