Detectionmediumtest
Potentially Suspicious AccessMask Requested From LSASS
Detects process handle on LSASS process with certain access mask
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Launch
Roberto Rodriguez (Cyb3rWard0g), Teymur Kheirkhabarov, Dimitrios Slamaris, Mark Russinovich, Aleksey Potapov, oscd.communityCreated Fri Nov 01Updated Tue Dec 194a1b6da0-d94f-4fc3-98fc-2d9cb9e5ee76windows
Log Source
Windowssecurity
ProductWindows← raw: windows
Servicesecurity← raw: security
Detection Logic
Detection Logic13 selectors
detection:
selection_1:
EventID: 4656 # A handle to an object was requested.
ObjectName|endswith: '\lsass.exe'
AccessMask|contains:
- '0x40'
- '0x1400'
# - '0x1000' # minimum access requirements to query basic info from service
- '0x100000'
- '0x1410' # car.2019-04-004
- '0x1010' # car.2019-04-004
- '0x1438' # car.2019-04-004
- '0x143a' # car.2019-04-004
- '0x1418' # car.2019-04-004
- '0x1f0fff'
- '0x1f1fff'
- '0x1f2fff'
- '0x1f3fff'
selection_2:
EventID: 4663 # An attempt was made to access an object
ObjectName|endswith: '\lsass.exe'
AccessList|contains:
- '4484'
- '4416'
filter_main_specific:
ProcessName|endswith:
- '\csrss.exe'
- '\GamingServices.exe'
- '\lsm.exe'
- '\MicrosoftEdgeUpdate.exe'
- '\minionhost.exe' # Cyberreason
- '\MRT.exe' # MS Malware Removal Tool
- '\MsMpEng.exe' # Defender
- '\perfmon.exe'
- '\procexp.exe'
- '\procexp64.exe'
- '\svchost.exe'
- '\taskmgr.exe'
- '\thor.exe' # THOR
- '\thor64.exe' # THOR
- '\vmtoolsd.exe'
- '\VsTskMgr.exe' # McAfee Enterprise
- '\wininit.exe'
- '\wmiprvse.exe'
- 'RtkAudUService64' # https://medium.com/falconforce/the-curious-case-of-realtek-and-lsass-33fc0c8482ff
ProcessName|contains:
- ':\Program Files (x86)\'
- ':\Program Files\'
- ':\ProgramData\Microsoft\Windows Defender\Platform\'
- ':\Windows\SysNative\'
- ':\Windows\System32\'
- ':\Windows\SysWow64\'
- ':\Windows\Temp\asgard2-agent\'
filter_main_generic:
ProcessName|contains: ':\Program Files' # too many false positives with legitimate AV and EDR solutions
filter_main_exact:
ProcessName|endswith:
- ':\Windows\System32\taskhostw.exe'
- ':\Windows\System32\msiexec.exe'
- ':\Windows\CCM\CcmExec.exe'
filter_main_sysmon:
ProcessName|endswith: ':\Windows\Sysmon64.exe'
AccessList|contains: '%%4484'
filter_main_aurora:
ProcessName|contains: ':\Windows\Temp\asgard2-agent-sc\aurora\'
ProcessName|endswith: '\aurora-agent-64.exe'
AccessList|contains: '%%4484'
filter_main_scenarioengine:
# Example: C:\a70de9569c3a5aa22184ef52a890177b\x64\SCENARIOENGINE.EXE
ProcessName|endswith: '\x64\SCENARIOENGINE.EXE'
AccessList|contains: '%%4484'
filter_main_avira1:
ProcessName|contains|all:
- ':\Users\'
- '\AppData\Local\Temp\is-'
ProcessName|endswith: '\avira_system_speedup.tmp'
AccessList|contains: '%%4484'
filter_main_avira2:
ProcessName|contains: ':\Windows\Temp\'
ProcessName|endswith: '\avira_speedup_setup_update.tmp'
AccessList|contains: '%%4484'
filter_main_snmp:
ProcessName|endswith: ':\Windows\System32\snmp.exe'
AccessList|contains: '%%4484'
filter_main_googleupdate:
ProcessName|contains: ':\Windows\SystemTemp\'
ProcessName|endswith: '\GoogleUpdate.exe'
AccessList|contains: '%%4484'
filter_optional_procmon:
ProcessName|endswith:
- '\procmon64.exe'
- '\procmon.exe'
AccessList|contains: '%%4484'
condition: 1 of selection_* and not 1 of filter_main_* and not 1 of filter_optional_*False Positives
Legitimate software accessing LSASS process for legitimate reason; update the whitelist with it
MITRE ATT&CK
Tactics
Sub-techniques
CAR Analytics
2019-04-004 · CAR 2019-04-004
Rule Metadata
Rule ID
4a1b6da0-d94f-4fc3-98fc-2d9cb9e5ee76
Status
test
Level
medium
Type
Detection
Created
Fri Nov 01
Modified
Tue Dec 19
Author
Path
rules/windows/builtin/security/win_security_susp_lsass_dump_generic.yml
Raw Tags
attack.credential-accesscar.2019-04-004attack.t1003.001