Detect Match Legitimate Resource Name or Location in CrowdStrike LogScale
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/
LogScale Detection Query
#event_simpleName=ProcessRollup2
| ImageFileName = /(?i)\\(svchost|csrss|lsass|services|smss|wininit|conhost|dllhost|RuntimeBroker|msdtc|wuauclt|taskhostw|spoolsv)\.exe$/
| !ImageFileName = /(?i)^C:\\Windows\\(System32|SysWOW64)\\/
| ParentBaseFileName := replace(ParentImageFileName, /^.*\\/, "")
| ProcessName := replace(ImageFileName, /^.*\\/, "")
| ParentMismatch := case {
ProcessName = /(?i)^svchost\.exe$/ and !ParentBaseFileName = /(?i)^services\.exe$/ : "true" ;
ProcessName = /(?i)^lsass\.exe$/ and !ParentBaseFileName = /(?i)^wininit\.exe$/ : "true" ;
ProcessName = /(?i)^csrss\.exe$/ and !ParentBaseFileName = /(?i)^(smss|csrss)\.exe$/ : "true" ;
ProcessName = /(?i)^services\.exe$/ and !ParentBaseFileName = /(?i)^wininit\.exe$/ : "true" ;
* : "false"
}
| groupBy([ComputerName, UserName, ImageFileName, ParentImageFileName, CommandLine, SHA256HashData], function=count(aid, as=EventCount))
| sort(EventCount, order=desc)
| select([ComputerName, UserName, ProcessName, ImageFileName, ParentBaseFileName, ParentImageFileName, ParentMismatch, CommandLine, SHA256HashData, EventCount])CrowdStrike LogScale (Falcon) query detecting T1036.005 by identifying ProcessRollup2 events where known system process names execute outside System32/SysWOW64, with parent process relationship validation for high-value targets (svchost, lsass, csrss, services). Groups by host and process attributes for efficient analyst triage.
Data Sources
Required Tables
False Positives & Tuning
- CrowdStrike Falcon sensor updates or self-healing processes that temporarily launch named child processes from non-standard sensor staging directories during version rollout
- Application virtualization solutions (e.g., VMware ThinApp, Microsoft App-V) that encapsulate system process executables within virtual filesystem containers at non-standard paths
- Custom IT operations scripts that spawn renamed copies of system executables in scratch directories for log collection or diagnostic data gathering purposes
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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