Detect Match Legitimate Resource Name or Location in Microsoft Sentinel
Adversaries may match or approximate the name or location of legitimate files, Registry keys, or other resources when naming/placing them. This is done for the sake of evading defenses and observation. This may be done by placing an executable in a commonly trusted directory (ex: under System32) or giving it the name of a legitimate, trusted program (ex: svchost.exe). In containerized environments, a threat actor may create a resource in a trusted namespace or one that matches the naming convention of a container pod or cluster.
MITRE ATT&CK
- Tactic
- Defense Evasion
- Technique
- T1036 Masquerading
- Sub-technique
- T1036.005 Match Legitimate Resource Name or Location
- Canonical reference
- https://attack.mitre.org/techniques/T1036/005/
KQL Detection Query
let SystemProcessPaths = dynamic([
@"C:\Windows\System32\svchost.exe",
@"C:\Windows\System32\csrss.exe",
@"C:\Windows\System32\lsass.exe",
@"C:\Windows\System32\services.exe",
@"C:\Windows\System32\smss.exe",
@"C:\Windows\System32\wininit.exe",
@"C:\Windows\System32\conhost.exe",
@"C:\Windows\System32\dllhost.exe",
@"C:\Windows\System32\RuntimeBroker.exe"
]);
DeviceProcessEvents
| where Timestamp > ago(24h)
| where FileName in~ ("svchost.exe", "csrss.exe", "lsass.exe", "services.exe", "smss.exe", "wininit.exe", "conhost.exe", "dllhost.exe", "RuntimeBroker.exe", "taskhostw.exe", "spoolsv.exe", "msdtc.exe", "wuauclt.exe", "vmtoolsd.exe")
| where not(FolderPath in~ (SystemProcessPaths))
| where not(FolderPath startswith @"C:\Windows\System32\" or FolderPath startswith @"C:\Windows\SysWOW64\")
| extend ParentMismatch = case(
FileName =~ "svchost.exe" and InitiatingProcessFileName !~ "services.exe", true,
FileName =~ "csrss.exe" and InitiatingProcessFileName !in~ ("smss.exe", "csrss.exe"), true,
FileName =~ "lsass.exe" and InitiatingProcessFileName !~ "wininit.exe", true,
FileName =~ "services.exe" and InitiatingProcessFileName !~ "wininit.exe", true,
false)
| project Timestamp, DeviceName, AccountName, FileName, FolderPath, ProcessCommandLine,
InitiatingProcessFileName, ParentMismatch, SHA256
| sort by Timestamp descDetects processes using names of critical Windows system binaries executing from non-standard locations. Adds parent process validation — svchost.exe should be spawned by services.exe, csrss.exe by smss.exe, lsass.exe by wininit.exe. Used extensively by Volt Typhoon, Gamaredon, APT41, and many ransomware families.
Data Sources
Required Tables
False Positives & Tuning
- VMware Tools (vmtoolsd.exe) running from non-default install locations in virtualized environments
- Application compatibility fixes that redirect binary execution paths
- Windows Feature on Demand or Windows Sandbox creating system binary copies in temporary locations
- Some endpoint protection tools that create copies of system binaries for analysis
Other platforms for T1036.005
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Execute svchost.exe from User Temp Directory
Expected signal: Sysmon Event ID 1: Process Create with Image=%TEMP%\svchost.exe, ParentImage not services.exe. OriginalFileName=Cmd.Exe mismatch with current name svchost.exe.
- Test 2Masquerade as lsass.exe in AppData
Expected signal: Sysmon Event ID 1: Process Create with Image=%APPDATA%\lsass.exe. Parent process will not be wininit.exe (ParentMismatch=TRUE).
- Test 3Masquerade Process Name on Linux
Expected signal: Process creation event showing /tmp/kworker executing. On systems with auditd, SYSCALL execve event for /tmp/kworker. /proc/<PID>/exe will point to /tmp/kworker.
References (6)
- https://attack.mitre.org/techniques/T1036/005/
- https://www.elastic.co/blog/how-hunt-masquerade-ball
- https://www.aquasec.com/blog/leveraging-kubernetes-rbac-to-backdoor-clusters/
- https://x.com/ItsReallyNick/status/1055321652777619457
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1036.005/T1036.005.md
- https://docs.docker.com/engine/reference/commandline/images/
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