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Anyway, adding malware exclusions like in the case of the DeroHE ransomware payload (iobit.dll), can have an impact on malware persistence.The idea of adding Defender exclusions can be dangerous in targeted attacks. It seems rather stupid in the wide-spread attacks:
In the targeted attacks, this method can be used for lateral movement and can increase the time of penetrating the Enterprise network until finally it will be detected by Defender.
- The computer is already highly compromised, because malware has got high privileges.
- Adding exclusions by the malware do not stop the behavior monitoring (protected by Tamper Protection), so the malware can be still detected in the cloud.
- Adding exclusions increases the chances of the proper detection in the cloud.
In the case of the IOBIT malware, the attacker did not get any gain of adding exclusions.
As you scroll through the tool, you’ll notice a section that covers control for Microsoft’s Attack Surface Reduction (ASR) rules. You’ll also note that many of them are disabled. These are among the most overlooked settings in Microsoft Defender. While you will need an Enterprise license to fully expose monitoring across your network, even standalone computers and small businesses can take advantage of these settings and protections. As noted in a recent document, Microsoft Defender Attack Surface Reduction recommendations, there are several settings that should be safe for most environments.
The recommended settings to enable include:
Turning these settings “on” — meaning they block the action — usually won’t adversely impact even standalone computers. You can use the tool to set these values and review any impact on your system. Most likely you won’t even realize they’re better protecting you.
- Block untrusted and unsigned processes that run from USB.
- Block Adobe Reader from creating child processes.
- Block executable content from email client and webmail.
- Block JavaScript or VBScript from launching downloaded executable content.
- Block credential stealing from the Windows local security authority subsystem (lsass.exe).
- Block Office applications from creating executable content.
Next, there are settings that should be reviewed for your environment to ensure they don’t interfere with your business or computing needs. These settings are:
In particular, in an environment that includes Outlook and Teams a great number of events were registered if the setting of “Block all office applications from creating child processes” was turned on. Again, you can try these and see if you are affected.
- Block Office applications from injecting code into other processes.
- Block Win32 API calls from Office Macros.
- Block all Office applications from creating child processes.
- Block execution of potentially obfuscated scripts.
The settings to watch out for include these:
These settings should be reviewed to make sure they don’t hinder line-of-business apps and business processes. For example, while “Use advanced protection against ransomware” sounds like a setting everyone would want, in one business where a team had developed internal-use software, it created issues with developer workflows. (This setting specifically scans executable files entering the system to determine whether they are trustworthy. If the files resemble ransomware, this rule blocks them from running.)
- Block executable files from running unless they meet a prevalence, age, or trusted list criterion.
- Use advanced protection against ransomware.
- Block process creations originating from PSExec and WMI-commands.
- Block all Office communication applications from creating child processes.
The setting, “Block process creations originating from PSExec and WMI-commands,” was especially troublesome, according to the authors. Not only did the setting lead to a large number of events in the audit log, it is incompatible with Microsoft Endpoint Configuration Manager, as the configuration manager client needs WMI commands to function properly.
Sounds like "Block process creations originating from PSExec and WMI commands" is only problematic in enterprise environments.Thanks.
In the article is included an interesting link about ASR rules after using them for two years in the business environment:
Microsoft Defender Attack Surface Reduction recommendations | Palantir Blog (medium.com)
One of the users who tested ConfigureDefender reported that this rule had significantly increased the boot time of his laptop without any record in the Log. I suspect that also the laptop firmware can use sometimes WMI.Sounds like "Block process creations originating from PSExec and WMI commands" is only problematic in enterprise environments.
I enable this rule and will test it some days
I don't compare time before and now but looks like boot time is equal.One of the users who tested ConfigureDefender reported that this rule had significantly increased the boot time of his laptop without any record in the Log. I suspect that also the laptop firmware can use sometimes WMI.
If these issues are absent, then enabling this rule is recommended.
Those settings are a little bit different from your high profile.Thanks.
In the article is included an interesting link about ASR rules after using them for two years in the business environment:
Microsoft Defender Attack Surface Reduction recommendations | Palantir Blog (medium.com)
These settings are from companie side of view, so they have different use caseThose settings are a little bit different from your high profile.
Especially: not enabling use advanced protection against ransomware and enabling block credential stealing from the Windows local security authority subsystem (lsass.exe).
Are you planning to change those settings on the high profile?
Yes, I know that, but I had for example a block from the advanced ransomware protection on my son's computer when updating an application.These settings are from companie side of view, so they have different use case
The HIGH Protection Level is optimal for the home environment as a starting point. Some users will have to use exclusions or disable one or more rules (like you), and others will be able to enable additional rules (like @SecurityNightmares). This can depend on the software installed on the computer.Yes, I know that, but I had for example a block from the advanced ransomware protection on my son's computer when updating an application.
So, is that setting still needed/recommended for a computer from a normal/home user?
I'm interested in Andy's opinion.
He chose those settings for a reason.
It was Elgato Stream Deck Software.The HIGH Protection Level is optimal for the home environment as a starting point. Some users will have to use exclusions or disable one or more rules (like you), and others will be able to enable additional rules (like @SecurityNightmares). This can depend on the software installed on the computer.
By the way, what was this application?
Could you make an exclusion?It was Elgato Stream Deck Software.
Elgato Stream Deck Software Release Notes
======================================================================= Source: https://help.elgato.com/admin/content-management/articles/2793637-elgato-stream-deck-software-release-notes/...help.elgato.com
The software is now up to date. It was just the internal updater that triggered that rule.Could you make an exclusion?
The blocked updater executable should be in the ConfogireDefender Log. You can search the log via the "ransomware" string. If the blocked entry is in the application folder, then you may exclude it. But, if the updates are rare, then you can turn this rule to Audit temporarily and make the update without exclusions as well.The software is now up to date. It was just the internal updater that triggered that rule.
Maybe next time setting it on audit for the update and back to enabled afterwards creates an automatic exclusion?
Recently installed Configure Defender on Windows 10 (Windows Defender fully operating) and I think I have set it on High setting by following the instructions in the folder ie High Button, then Refresh Button then Reboot
When I then open Config Defender there is no way I can determine which level Config Defender is set to ie Default, High, Max. I would have expected at least the High Button to be highlighted.
The image I have enclosed shows Basic Defender Settings underneath the three Buttons.
My question is:- How do I know which Protection Level has been set?
Is there something I am not doing?
It's on High.
Click on Default, look at the values show. Then click on High and look again at the values shown.