Command Obfuscation via Unicode Modifier Letters

Last updated a day ago on 2025-11-13
Created a day ago on 2025-11-13

About

Identifies the presence of unicode modifier letters in the process command_line. Adversaries sometimes replace ASCII characters with visually similar Unicode modifier letters or combining marks to evade simple string-based detections.
Tags
Domain: EndpointOS: WindowsUse Case: Threat DetectionTactic: Defense EvasionData Source: Elastic EndgameData Source: Elastic DefendData Source: Windows Security Event LogsData Source: Microsoft Defender for EndpointData Source: SysmonData Source: SentinelOneData Source: CrowdstrikeLanguage: eql
Severity
high
Risk Score
73
MITRE ATT&CK™

Defense Evasion (TA0005)(opens in a new tab or window)

License
Elastic License v2(opens in a new tab or window)

Definition

Rule Type
Event Correlation Rule
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
endgame-*logs-crowdstrike.fdr*logs-endpoint.events.process-*logs-m365_defender.event-*logs-sentinel_one_cloud_funnel.*logs-system.security*logs-windows.forwarded*logs-windows.sysmon_operational-*winlogbeat-*
Related Integrations

endpoint(opens in a new tab or window)

windows(opens in a new tab or window)

system(opens in a new tab or window)

m365_defender(opens in a new tab or window)

sentinel_one_cloud_funnel(opens in a new tab or window)

crowdstrike(opens in a new tab or window)

Query
process where host.os.type == "windows" and event.type == "start" and
 (
   process.name : ("reg.exe", "net.exe", "net1.exe", "certutil.exe", "MSHTA.EXE", "msiexec.exe", "bitsadmin.exe", "CertReq.exe", "PrintBrm.exe", "MSBuild.exe", "wuauclt.exe", "curl.exe", "wget.exe", "ssh.exe", "Cmd.Exe", "PowerShell.EX", "CONHOST.EXE", "wscript.exe", "cscript.exe", "REGSVR32.EXE", "RUNDLL32.EXE", "procdump.exe", "ntdsutil.exe", "diskshadow.exe", "schtasks.exe", "sc.exe", "wmic.exe", "VSSADMIN.EXE", "WBADMIN.EXE", "iCACLS.EXE", "sftp.exe", "scp.exe", "esentutl.exe", "InstallUtil.exe", "wevtutil.exe") or
   ?process.pe.original_file_name in ("reg.exe", "net.exe", "net1.exe", "CertUtil.exe", "MSHTA.EXE", "msiexec.exe", "bitsadmin.exe", "CertReq.exe", "PrintBrm.exe", "MSBuild.exe", "wuauclt.exe", "curl.exe", "wget.exe", "ssh.exe", "Cmd.Exe", "PowerShell.EX", "CONHOST.EXE", "wscript.exe", "cscript.exe", "REGSVR32.EXE", "RUNDLL32.EXE", "procdump", "ntdsutil.exe", "diskshadow.exe", "schtasks.exe", "sc.exe", "wmic.exe", "VSSADMIN.EXE", "WBADMIN.EXE", "iCACLS.EXE", "sftp.exe", "scp.exe", "esentutl.exe", "InstallUtil.exe", "wevtutil.exe")
 ) and
 process.command_line regex """.*[ʰ-˿ᴬ-ᶻ]+.*"""

Install detection rules in Elastic Security

Detect Command Obfuscation via Unicode Modifier Letters in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).