- Nov 15, 2016
- 867
And if so, do you know the PS commands for adding them?
This Enable ASR rules individually to protect your organization might help. Under "Use PowerShell to enable or audit Attack surface reduction rules"
And if so, do you know the PS commands for adding them?
Thanks, @shmu26....
Add-MpPreference -AttackSurfaceReductionRules_Ids 9e6c4e1f-7d60-472f-ba1a-a39ef669e4b2 -AttackSurfaceReductionRules_Actions Enabled
"Block credential stealing from the Windows local security authority subsystem (lsass.exe)"
...
Yeah, the powershell commands work. I was kinda hoping for a tutorial that held my hand a little more tightly, but it does work.This Enable ASR rules individually to protect your organization might help. Under "Use PowerShell to enable or audit Attack surface reduction rules"
Set-MpPreference -AttackSurfaceReductionRules_Ids BE9BA2D9-53EA-4CDC-84E5-9B1EEEE46550,D4F940AB-401B-4EFC-AADC-AD5F3C50688A,3B576869-A4EC-4529-8536-B80A7769E899,75668C1F-73B5-4CF0-BB93-3ECF5CB7CC84,D3E037E1-3EB8-44C8-A917-57927947596D,5BEB7EFE-FD9A-4556-801D-275E5FFC04CC,92E97FA1-2EDF-4476-BDD6-9DD0B4DDDC7B -AttackSurfaceReductionRules_Actions Enabled,Enabled,Enabled,Enabled,Enabled,Enabled,Enabled
Set-MpPreference -AttackSurfaceReductionRules_Ids BE9BA2D9-53EA-4CDC-84E5-9B1EEEE46550,D4F940AB-401B-4EFC-AADC-AD5F3C50688A,3B576869-A4EC-4529-8536-B80A7769E899,75668C1F-73B5-4CF0-BB93-3ECF5CB7CC84,D3E037E1-3EB8-44C8-A917-57927947596D,5BEB7EFE-FD9A-4556-801D-275E5FFC04CC,92E97FA1-2EDF-4476-BDD6-9DD0B4DDDC7B -AttackSurfaceReductionRules_Actions Disabled,Disabled,Disabled,Disabled,Disabled,Disabled,Disabled
The ASR rule for lsass is now operative, in Windows 10 Pro 1803.Thanks. That clears up my registry question.
The remaining question is whether
5. "Block credential stealing from the Windows local security authority subsystem (lsass.exe)" (9e6c4e1f-7d60-472f-ba1a-a39ef669e4b2)
actually does anything on win 10 pro.
Microsoft documentation says that Credential Guard is not present in the pro editions, only in Enterprise and Education. So maybe this lsass.exe rule is not really doing anything?
Also for me, the ransomware rule is silent.I am testing the new version of Configuredefender - added the ASR rules introduced in Windows 10 ver. 1803.
The below rules were confirmed to work:
There is no documentation for the rules, so I cannot say why the first rule blocks Configuredefender and does not block Hard_Configurator???
- Block executable files from running unless they meet a prevalence, age, or trusted list criteria
- Block process creations originating from PSExec and WMI commands
- Block untrusted and unsigned processes that run from USB
Some rules are hard to test, so I will test them soon:
The last two rules are completely silent on my computer.
- Use advanced protection against ransomware
- Block credential stealing from the Windows local security authority subsystem (lsass.exe)
This rule does not seem so useful in a default/deny setup. But in default/allow, I can see that it might be useful.My system is configured for testing all ASR rules set to ON. Furthermore, I am trying to understand how works the ASR rule:
"Block executable files from running unless they meet a prevalence, age, or trusted list criteria".
Here are my findings:
I am curious, how long this ASR rule will block the fresh compilation of ConfigureDefender in the location B. I am waiting for the Microsoft article on how this rule can be managed.
- The rule supports exclusions, but that worked well for me only after some reboots. I excluded C:\Windows and C:\Program Files ...
- All my already installed applications (in C:\Program Files...) and portable programs on the second disc could be executed without a problem, also the legal programs downloaded from the Internet.
- The fresh compilation of ConfigureDefender could be run from the excluded folder, but was blocked in other locations (A, B, ...).
- When I turned OFF the ASR rule temporarily and run the fresh compilation of ConfigureDefender in the location A, it was checked in Defender cloud and after several seconds Defender allowed it to run. Next, after I turned the ASR rule ON again, the fresh compilation of ConfigureDefender in the location A was NOT BLOCKED anymore. But, this was not true for the same file in another location B. So, this ASR rule could get the information from the Defender local AI about the previous file execution history.
Thanks for the report.Finally, I managed to confirm that the ASR rule:
Block credential stealing from the Windows local security authority subsystem (lsass.exe)
works on my computer. This rule was totally silent until today, when I noticed that it blocked
C:\Windows\System32\taskhostw.exe from accessing lsass.exe.
Next, I downloaded the tool Remote DLL : Simple & Free Tool to Inject or Remove DLL from Remote Process | www.SecurityXploded.com and ran it with admin rights. When I tried to choose the target process for injection, Windows showed the blocking alert, and I could see that lsass.exe is missing on the list of available target processes.
In the Event Viewer (Event Id 1121) I could check that C:\Program Files (x86)\SecurityXploded\Remote DLL\RemoteDll64.exe could not access lsass.exe.
As in the case of some other ASR rules, this rule woke up after some reboots. I tested it before with RemoteDll and there was not any blocking alert.
You can do it for ASR rules applied via Windows Policies (as administrator).Can you export ASR rules as a reg file from Regedit, and then import them on a different computer?
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR]
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\ASROnlyExclusions]
"C:\\Windows"=dword:00000000
"C:\\Program Files"=dword:00000000
"C:\\Program Files (x86)"=dword:00000000
"C:\\ProgramData\\Microsoft\\Windows Defender"=dword:00000000
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\Rules]
"BE9BA2D9-53EA-4CDC-84E5-9B1EEEE46550"=dword:00000001
"D4F940AB-401B-4EFC-AADC-AD5F3C50688A"=dword:00000001
"3B576869-A4EC-4529-8536-B80A7769E899"=dword:00000001
"75668C1F-73B5-4CF0-BB93-3ECF5CB7CC84"=dword:00000001
"D3E037E1-3EB8-44C8-A917-57927947596D"=dword:00000001
"5BEB7EFE-FD9A-4556-801D-275E5FFC04CC"=dword:00000001
"92E97FA1-2EDF-4476-BDD6-9DD0B4DDDC7B"=dword:00000001
"01443614-cd74-433a-b99e-2ecdc07bfc25"=dword:00000001
"9e6c4e1f-7d60-472f-ba1a-a39ef669e4b2"=dword:00000001
"d1e49aac-8f56-4280-b9ba-993a6d77406c"=dword:00000001
"b2b3f03d-6a65-4f7b-a9c7-1c7ef74a9ba4"=dword:00000001
"c1db55ab-c21a-4637-bb3f-a12568109d35"=dword:00000001
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR]
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\ASROnlyExclusions]
"C:\\Windows"=dword:00000000
"C:\\Program Files"=dword:00000000
"C:\\Program Files (x86)"=dword:00000000
"C:\\ProgramData\\Microsoft\\Windows Defender"=dword:00000000
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\Rules]
"BE9BA2D9-53EA-4CDC-84E5-9B1EEEE46550"=dword:00000001
"D4F940AB-401B-4EFC-AADC-AD5F3C50688A"=dword:00000001
"3B576869-A4EC-4529-8536-B80A7769E899"=dword:00000001
"75668C1F-73B5-4CF0-BB93-3ECF5CB7CC84"=dword:00000001
"D3E037E1-3EB8-44C8-A917-57927947596D"=dword:00000001
"5BEB7EFE-FD9A-4556-801D-275E5FFC04CC"=dword:00000001
"92E97FA1-2EDF-4476-BDD6-9DD0B4DDDC7B"=dword:00000001
"01443614-cd74-433a-b99e-2ecdc07bfc25"=dword:00000001
"9e6c4e1f-7d60-472f-ba1a-a39ef669e4b2"=dword:00000001
"d1e49aac-8f56-4280-b9ba-993a6d77406c"=dword:00000001
"b2b3f03d-6a65-4f7b-a9c7-1c7ef74a9ba4"=dword:00000001
"c1db55ab-c21a-4637-bb3f-a12568109d35"=dword:00000001
That's a nice hack. I will try that.You can do it for ASR rules applied via Windows Policies (as administrator).
The ASR rules applied via ConfigureDefender or PowerShell cmdlets require higher rights (System, WinDefend, TrustedInstaller).
Anyway, there is a simple way to transfer the rules made by ConfigureDefender (PowerShell cmdlets) to another computer (Windows Policies). One should export the rules (all ON in the below example):
.
Code:Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR] [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\ASROnlyExclusions] "C:\\Windows"=dword:00000000 "C:\\Program Files"=dword:00000000 "C:\\Program Files (x86)"=dword:00000000 [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\Rules] "BE9BA2D9-53EA-4CDC-84E5-9B1EEEE46550"=dword:00000001 "D4F940AB-401B-4EFC-AADC-AD5F3C50688A"=dword:00000001 "3B576869-A4EC-4529-8536-B80A7769E899"=dword:00000001 "75668C1F-73B5-4CF0-BB93-3ECF5CB7CC84"=dword:00000001 "D3E037E1-3EB8-44C8-A917-57927947596D"=dword:00000001 "5BEB7EFE-FD9A-4556-801D-275E5FFC04CC"=dword:00000001 "92E97FA1-2EDF-4476-BDD6-9DD0B4DDDC7B"=dword:00000001 "01443614-cd74-433a-b99e-2ecdc07bfc25"=dword:00000001 "9e6c4e1f-7d60-472f-ba1a-a39ef669e4b2"=dword:00000001 "d1e49aac-8f56-4280-b9ba-993a6d77406c"=dword:00000001 "b2b3f03d-6a65-4f7b-a9c7-1c7ef74a9ba4"=dword:00000001 "c1db55ab-c21a-4637-bb3f-a12568109d35"=dword:00000001
and next edit the registry path (adding Policies):
That is all.Code:Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR] [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\ASROnlyExclusions] "C:\\Windows"=dword:00000000 "C:\\Program Files"=dword:00000000 "C:\\Program Files (x86)"=dword:00000000 [HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\Rules] "BE9BA2D9-53EA-4CDC-84E5-9B1EEEE46550"=dword:00000001 "D4F940AB-401B-4EFC-AADC-AD5F3C50688A"=dword:00000001 "3B576869-A4EC-4529-8536-B80A7769E899"=dword:00000001 "75668C1F-73B5-4CF0-BB93-3ECF5CB7CC84"=dword:00000001 "D3E037E1-3EB8-44C8-A917-57927947596D"=dword:00000001 "5BEB7EFE-FD9A-4556-801D-275E5FFC04CC"=dword:00000001 "92E97FA1-2EDF-4476-BDD6-9DD0B4DDDC7B"=dword:00000001 "01443614-cd74-433a-b99e-2ecdc07bfc25"=dword:00000001 "9e6c4e1f-7d60-472f-ba1a-a39ef669e4b2"=dword:00000001 "d1e49aac-8f56-4280-b9ba-993a6d77406c"=dword:00000001 "b2b3f03d-6a65-4f7b-a9c7-1c7ef74a9ba4"=dword:00000001 "c1db55ab-c21a-4637-bb3f-a12568109d35"=dword:00000001
How did you make those folder exclusions?.
The mitigation "Block credential stealing from the Windows local security authority subsystem (lsass.exe)" can block some schtaks.exe processes and also processes started by Windows Defender in the folder: ProgramData\Microsoft\Windows Defender (both folders are excluded).
If I correctly remember the passwords to Microsoft account, Outlook and OneDrive are also stored in Lsass. Anyway, the "Lsass" rule does not support exclusions (it is marked by !! ), so they are for :How did you make those folder exclusions?
Ah, I get it now. The folder exclusions apply to all ASR rules, not just to lsass.
Do you think that these folder exclusions might weaken the other ASR rules? The lsass rule is probably not so important for home users, so maybe it is better to disable that particular rule, and then delete the folder exclusions?