Windows defender boot scan

Questions, concerns, or insights on this story? Read all Microsoft security intelligence blog posts. Follow us on Twitter MsftSecIntel. Skip to main content. To detect threats, it performs dynamic analysis using multiple new solution components that include: UEFI anti-rootkit, which reaches the firmware through Serial Peripheral Interface SPI Full filesystem scanner, which analyzes content inside the firmware Detection engine, which identifies exploits and malicious behaviors Firmware scanning is orchestrated by runtime events like suspicious driver load and through periodic system scans.

Windows Security notification showing detection of malicious content in non-volatile memory NVRAM Microsoft Defender ATP customers will also see these detections raised as alerts in Microsoft Defender Security Center, empowering security operations teams to investigate and respond to firmware attacks and suspicious activities at the firmware level in their environments.

Figure 4. Expected boot flow vs. Figure 5. Figure 6. Comprehensive security levels up with low-level protections The new UEFI scanner adds to a rich set of Microsoft technologies that integrate to deliver chip-to-cloud security, from a strong hardware root of trust to cloud-powered security solutions at the OS level. At Microsoft, we want users to be in control of their devices, including knowing the security health of these devices.

Sorry this didn't help. Thanks for your feedback. That is the black. If your PC restarted before the black screen appeared, in the past that has. To be a bit more specific about the following section of that informational event log entry above:.

Description: Windows Defender Antivirus Configuration has changed. The first portion is a generic section displayed in all such messages, that's really just indicating that the value change might be normal, unless you have some reason to suspect that it's not.

No, it's not really a user friendly statement, but as I mentioned in that other thread, it's not typically something the average consumer would be expected to read anyway. All this message itself means though is that the value itself has changed and thus the information log entry is simply indicting that fact, with no other meaning implied that I'm aware.

Glen knows far more about the operation of these boot time scans themselves, though it became clear to me after watching him troubleshoot a few that these operate within the Windows Recovery Environment WinRE , that's normally used to troubleshoot and repair common causes of unbootable operating systems.

So from my own observations, it appears that most problems with the operation of the Offline scan are likely due to either a problem passing configuration information into this WinRE environment or simply an issue with the operation of WinRE itself.

That's why as Glen stated a "Repair Upgrade" may be required and is also the reason that little information about the Offline scan results are available within the normal Windows operating system, since these 2 operating systems are completely independent and the normal operating system is in fact not really aware that the WinRE operating environment exists, since it operates outside the limits of it's own environment. Think of them as 2 worlds where the WinRE environment is only operating at special request and though aware of the normal operating system, typically doesn't write into or change the other's filing system unless something malicious is identified and removed.

However, once booted, the normal operating system isn't aware of what WinRE and the Offline scan has done unless it were to pass something via an additional file, which I'm not certain that it does.

Maybe Glen can shed some light on this from his own observations? Note though that troubleshooting the Offline scan operation without this knowledge is simply guesswork and experimentation. It also likely runs at least a portion of a Quick scan, since this always checks all locations that malware is known to operate. Full scans are never necessary and only performed in order to insure that "dropper" files like malware installers don't remain on a previously infected system or other leftovers aren't left in places like temporary file folders.

In truth, since these items aren't actually operating, they don't really cause a problem except that they often create confusion when detected and are much more likely to cause a false positive detection as well. Thank you very much for your thoughtful reply. I must change the info for I have just tried to do a "boot time" scan again on the older Asus and it also worked this time.

I also remember that the older Asus came with an out of the box installation of McAfee which I uninstalled and of which I had forgotten. As I conjecture now if one has an error of " If this is an unexpected event you should review the settings as this may be the result of malware.

I have used many virus protection programs in the past and have done many "boot time" scans and they always behaved differently from this and you explained why though I would like to suggest this. The point of the "boot time" scan, as I am sure you know, is that it is done without the OS.

It then becomes impossible to scan with out the OS and so it is not called "boot time" scan but "offline scan". I just installed another virus protection program in the older HP laptop with Win 10 and the "Boot Time" scan worked as usual however that laptop still has "BIOS". I would like to note that in the past I have run a full scan at boot time offered by an AV program and they identified zip files that where corrupted but did not have a virus that was named that seem to have been missed by a scan in the OS and certainly would have been missed by a scan of only the OS files.

This of course is seen as superstition by most but I think the "command line" sees things that the OS can not and clearly that is why I think a true "boot time" scan for viruses is so important. OneDrive Windows 7 and 8. Copy and Paste Between Android and Windows.

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How-To Geek is where you turn when you want experts to explain technology. Feedback will be sent to Microsoft: By pressing the submit button, your feedback will be used to improve Microsoft products and services. Privacy policy. Microsoft Defender Offline is an antimalware scanning tool that lets you boot and run a scan from a trusted environment. The scan runs from outside the normal Windows kernel so it can target malware that attempts to bypass the Windows shell, such as viruses and rootkits that infect or overwrite the master boot record MBR.

You can use Microsoft Defender Offline if you suspect a malware infection, or you want to confirm a thorough clean of the endpoint after a malware outbreak. In previous versions of Windows, a user had to install Microsoft Defender Offline to bootable media, restart the endpoint, and load the bootable media. Microsoft Defender Offline in Windows 10 and Windows 11 has the same hardware requirements as Windows Minimum hardware requirements. Hardware component guidelines.

To run Microsoft Defender Offline from the endpoint, the user must be logged in with administrator privileges.