Elastic Defend high stable eql

Suspicious PowerShell Execution

Identifies the execution of PowerShell with suspicious argument values. This behavior is often observed during malware installation leveraging PowerShell.

View Source

Detection Logic

process where event.action == "start" and process.name : "powershell.exe" and process.parent.executable != null and

 not user.id : "S-1-5-18" and

 /*
 following exclusions are covered by other rules
  - Suspicious Execution via Windows Management Instrumentation
  - Suspicious Windows Schedule Child Process
  - PowerShell Obfuscation Spawned via Microsoft Office
  - Suspicious PowerShell Execution via Windows Scripts
 */

 not (process.parent.executable :
              ("?:\\Windows\\System32\\svchost.exe",
               "?:\\Windows\\System32\\wbem\\WmiPrvSe.exe",
               "?:\\Program Files\\*.exe",
               "?:\\Program Files (x86)\\*.exe",
               "?:\\Users\\*\\AppData\\Local\\gitkraken\\app-*\\gitkraken.exe",
               "?:\\Windows\\System32\\taskeng.exe",
               "?:\\Windows\\cybercnsagent\\cybercnsagent.exe",
               "?:\\Windows\\SysWOW64\\WindowsPowerShell\\*\\powershell_ise.exe",
               "?:\\Windows\\System32\\WindowsPowerShell\\*\\powershell_ise.exe",
               "?:\\ProgramData\\Microsoft\\Windows Defender Advanced Threat Protection\\Platform\\*\\SenseIR.exe") and not process.parent.name : "java.exe") and

 not process.parent.name : ("wscript.exe", "cscript.exe") and

 not (process.args:"-NonInteractive" and process.args :"-InputFormat") and
 not (process.args : ("RemoteSigned", "-ExecutionPolicy", "write-host") and
      not process.parent.name : ("explorer.exe", "python.exe", "cmd.exe")) and
 not process.args : "[System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String('cGFzc3dvcmQ='))" and
 not (process.command_line : "*echo ~/.ansible/tmp/ansible-tmp*" and process.parent.executable : "C:\\Windows\\System32\\OpenSSH\\sshd.exe") and
 not (process.args : "$OutputEncoding = [System.Text.Encoding]::UTF8; $b64='eyJjb252ZXJzYXRpb25faWQiOiJ*" and process.parent.name : "Cursor.exe") and 
 not process.command_line :
            ("*ConvertTo-Json*Write-Host*",
             "*BrowserExtension.dll*WebCompanion.BrowserExtension*",
             "*-ExecutionPolicy*Write-Verbose*",
             "*webClient.Headers.add*",
             "*System.Management.Automation.Host.Size*",
             "*JABQAHIAbwBnAHIAZQBzAHMAUAByAGUAZgBlAHIAZQ*",
             "*chocolatey.org*",
             "*Get-WmiObject*",
             "*artifacts.elastic.co*", 
             "*officecdn.microsoft.com*",
             "*CgAgACAAIAAgACAAIAAgACAAJABTAGMAcgBpAHAAdAAgACA*",
             "*Program Files*",
             "*).Access.IdentityReference;$defaults*",
             "*https://repo.maven.apache.org*", 
             "*\\CSIWorking\\system\\WinSCP\\winscp.com*", 
             "*@Files.onetech.cc*", 
             "*Register-AzureADConnectHealthADDSAgent*", 
             "*\\ProgramData\\Microsoft\\LogConverter\\*", 
             "*WinSCP.com*",
             "*SNC_isWmi*",
             "*--app-id=memtime-*", 
             "*BkAGEAdABhAGIAYQBzAGUALgB3AGkAbgBkAG8AdwBzAC4AbgBlAHQA*",
             "*FsAdgBlAHIAcwBpAG8AbgBdACQAbQBpAG4AaQBtAHUAbQBWAGUAcgBzAGkAbwBuACAAPQAgACcAMgAuADIALgAwACcA*",
             "*https://tshf.sas.com/techsup/download/hotfix/*",
             "*scripts\\buildsystems\\msbuild*",
             "*.vscode\\extensions\\ms-dynamics-smb*",
             "*$ErrorActionPreference*$adsiMember*",
             "*$ErrorActionPreference*$rgx_log4j*",
             "*$env:APPDATA\"+'\\Browser Assistant\\*",
             "*APPDATA\"+'/Browser Extension/BE.txt*",
             "*$env:APPDATA\"+'/BBWC/*",
             "*ReadAllBytes($w+'Newtonsoft.Json.dll*",
             "*https://go.microsoft.com/fwlink*",
             "*krsfile:////LOBCS*",
             "*ProgramData\\VinitySoft Data\\MariaDb\\*",
             "*\\Temp\\claude\\claude-pwd-ps-*",
             "*https://10.55.138.214:443/downloads/*",
             "\"C:\\Windows\\SysWOW64\\WindowsPowerShell\\v1.0\\powershell.exe\" -noexit -command \"[reflection.assembly]::loadFrom('.\\RD-PSAPI.dll')
| import-module\"",
             "*-noni -nop -w 1 -enc *AEUAbABhAHMAdABpAGMAfABUAHIAZQBsAGwAaQB4ACIA*",
             "*-noni -nop -w 1 -enc *AEUAbABhAHMAdABpAGMAIABBAGcAZQBuAHQAIgA=*",
             "*JABjAGwAcwA9ACcATQBvAHUAcwBlACcAOwAKACAAIABHAGUAdAAtAEMAaQBtAEkAbgBzAHQAYQBuAGMAZQAgAFcAaQBuADMAMgBfAFAAbgBQAEUAbgB0AGkAdAB5ACAALQBGAGkAb*",
             "*JABjAGwAcwA9ACcASwBlAHkAYgBvAGEAcgBkACcAOwAKACAAIABHAGUAdAAtAEMAaQBtAEkAbgBzAHQAYQBuAGMAZQAgAFcAaQBuADMAMgBfAFAAbgBQAEUAbgB0AGkAdAB5ACAALQBGAGkAb*",
             "*JABjAHYAIAA9ACAARwBlAHQALQBJAHQAZQBtAFAAcgBvAHAAZQByAHQAeQAgACcASABLAEwATQA6AFwAUwBPAEYAVABXAEEAUgBFAFwATQBpAGMAcgBvAHMAbwBmAHQAXABXAGkAbgBkAG8AdwBzACAATgBUAFwAQwB1AHIAcgBlAG4AdABWAGUAcgBzAGkAbwBuACcACgAiACQAKAAkAGMAdgAuAFAAcgBvAGQAdQBjAHQATgBhAG0AZQApAHwAJAAoACQAYwB2AC4ARABpAHMAcABsAGEAeQBWAGUAcgBzAGkAbwBuACkAf*",
             /* inventory tooling checking the installed Chrome version: $ErrorActionPreference='silentlycontinue'; $tmp = (Get-Item -Path "$env:PROGRAMFILES\Google\Chrome\Application\chrome.exe") */
             "*JABFAHIAcgBvAHIAQQBjAHQAaQBvAG4AUAByAGUAZgBlAHIAZQBuAGMAZQA9ACcAcwBpAGwAZQBuAHQAbAB5AGMAbwBuAHQAaQBuAHUAZQAnADsAIAAkAHQAbQBwACAAPQAgACgARwBlAHQALQBJAHQAZQBtACAALQBQAGEAdABoACAAIgAkAGUAbgB2ADoAUABSAE8ARwBSAEEATQBGAEkATABFAFMAXABHAG8AbwBnAGwAZQBcAEMAaAByAG8AbQBlAFwA*",
             /* base64 alignment variant of the Az.Accounts minimum version check already excluded above: \n$ErrorActionPreference = 'Stop'\n[version]$minimumVersion = '2.2.0' */
             "*CgAkAEUAcgByAG8AcgBBAGMAdABpAG8AbgBQAHIAZQBmAGUAcgBlAG4AYwBlACAAPQAgACcAUwB0AG8AcAAnAAoAWwB2AGUAcgBzAGkAbwBuAF0AJABtAGkAbgBpAG0AdQBtAFYAZQByAHMAaQBvAG4A*") and
 not process.parent.args : "([Datetime]::ParseExact($_.InstalledOn," and
 not process.command_line : ("PowerShell*hkguTzSCb75g7sJ9ChMcmAOPpeBL9ZJy/tejnoCjT+E=*", "*.LastWriteTime.ToFileTime*", "*New-Object*Net.Mail.SmtpClien*") and
 not (process.parent.name : "cmd.exe" and
      (process.parent.command_line : "*\\WindowsPowershell\\*\\powershell*" or process.parent.args : ("-Command", "-OutputFormat", "-InputFormat"))) and

 not process.parent.name : "powershell.exe" and

 not (process.parent.name : "cmd.exe" and process.parent.args : ("*.cmd", "*.bat") and process.command_line: "*Get-Content*Set-Content*") and

 not (process.args : "NT\\CurrentVersion').InstallationType;" and process.args : "[System.Text.Encoding]::UTF8.GetBytes($OutStr);") and

 not (process.parent.code_signature.trusted == true and process.parent.code_signature.subject_name in ("ControlCase LLC", "HashiCorp, Inc.", "JetBrains s.r.o.", "Johannes Schindelin", "Anomaly Innovations, Inc https://anoma.ly/", "Anthropic, PBC", "Anysphere, Inc.", "Denver Technologies, Inc. dba Warp")) and

 not process.parent.command_line :  "\"C:\\Windows\\system32\\cmd.exe\" " and

 not (process.parent.name : "Cursor.exe" and process.command_line : "* dotnet csharpier format*") and 

 not (process.parent.name : "codex*.exe" and process.args : "[Console]::OutputEncoding=[System.Text.Encoding]::UTF8;*") and 

 not process.working_directory : "C:\\ProgramData\\VinitySoft Data\\MariaDb\\" and

 not process.parent.executable : ("C:\\Users\\*\node_modules\\@openai\\codex\\bin\\codex-x86_64-pc-windows-msvc.exe",
                                  "C:\\Users\\*\\extensions\\openai.chatgpt-*\\bin\\windows-x86_64\\codex.exe",
                                  "C:\\Users\\*\\AppData\\Local\\Programs\\Microsoft VS Code\\Code.exe",
                                  "C:\\Users\\*\\@openai\\*\\x86_64-pc-windows-msvc\\codex\\codex.exe",
                                  "C:\\Python312\\python.exe",
                                  "?:\\Users\\*\\AppData\\Local\\Programs\\Antigravity\\resources\\app\\extensions\\antigravity\\bin\\language_server_windows_x64.exe",
                                  "?:\\Users\\*\\AppData\\Local\\Python\\bin\\python.exe",
                                  "?:\\Users\\*\\AppData\\Local\\Programs\\Python\\Python*\\python.exe",
                                  "?:\\Users\\*\\AppData\\Local\\Python\\pythoncore-*\\python.exe", 
                                  "D:\\Antigravity\\resources\\app\\extensions\\antigravity\\bin\\language_server_windows_x64.exe",  
                                  "?:\\Users\\*\\.codex\\.sandbox-bin\\codex-command-runner-*.exe") and

 not process.args :  ("$w=$env:LOCALAPPDATA+'/OPWC/';[Reflection.Assembly]::Load([System.IO.File]::ReadAllBytes($w+'OperaSharpDLL.dll'));[OperaSharpDLL.Helper]::Startup()",
                      "IEX (New-Object Net.WebClient).DownloadString('https://install.demo-toolkit.de/dtkupdater.ps1?apikey=*",
                      "D:\\PowerShell\\webclient.cmd",
                      "Invoke-WebRequest -Uri https://www.7-zip.org/a/7zr.exe -o '7zr.exe';",
                      "\"& 'C:\\Program Files (x86)\\combit\\*",
                      "Get-CimInstance -Namespace root\\wmi -ClassName WmiMonitorID
| *",
                      "& { Add-Type -A 'System.IO.Compression.FileSystem'; [IO.Compression.ZipFile]::CreateFromDirectory*") and

 not (process.parent.name : "cmd.exe" and
      process.parent.args : ("D:\\PowerShell\\webclient.cmd",  
                             "C:\\Temp\\FST-Robocopy-wEmailNotif.cmd", 
                             "C:\\istip-installation\\install.bat", 
                             "'C:\\ProgramData\\PatchBot\\data\\windows-health-after.json';", 
                             "'C:\\ProgramData\\PatchBot\\data\\windows-updates.json';", 
                             "'C:\\ProgramData\\PatchBot\\data\\windows-updates.json')")) and

 not (process.parent.executable : "C:\\Users\\*\\AppData\\Local\\Programs\\Microsoft VS Code\\Code.exe" and process.command_line : "*Windows.UI.Notifications*") and

 not (process.parent.executable : "C:\\Users\\*\\.vscode\\extensions\\openai.chatgpt*-win32-x64\\bin\\windows-x86_64\\codex.exe" and process.parent.args == "mcp") and

 not (process.parent.executable : "C:\\Windows\\System32\\msiexec.exe" and process.args : "https://go.microsoft.com/fwlink/p/?LinkId=*" and
      process.args :"$env:TEMP\\MicrosoftEdgeWebview2Setup.exe") and

 not process.args : "chcp 65001;[System.Reflection.Assembly]::LoadWithPartialName('System.Drawing');(New-Object System.Drawing.Text.InstalledFontCollection).Families" and

 (
  process.command_line :
        (
          "*^*^*^*^*^*^*^*^*^*",
          "*`*`*`*`*",
          "*+*+*+*+*+*+*",
          "*[char[]](*)*-join*",
          "*Base64String*",
          "*[*Convert]*",
          "*.Compression.*",
          "*-join($*",
          "*.replace*",
          "*MemoryStream*",
          "*WriteAllBytes*",
          "* -enc *",
          "* -ec *",
          "* /e *",
          "* /enc *",
          "* /ec *",
          "*WebClient*",
          "*DownloadFile*",
          "*DownloadString*",
          "* iex*",
          "*;iex*",
          "* iwr*",
          "*;iwr *",
          "*;saps *",
          "* aQB3AHIAIABpA*",
          "*Reflection.Assembly*",
          "*Assembly.GetType*",
          "*$env:temp\\*start*",
          "*powercat*",
          "*nslookup -q=txt*",
          "*$host.UI.PromptForCredential*",
          "*Net.Sockets.TCPClient*",
          "*curl *;Start*",
          "powershell.exe \"<#*",
          "*ssh -p *",
          "*http*
| iex*",
          "*@SSL\\DavWWWRoot\\*.ps1*",
          "*.lnk*.Seek(0x*",
          "*[string]::join(*",
          "*[Array]::Reverse($*",
          "* hidden $(gc *",
          "*=wscri& set*",
          "*http'+'s://*",
          "*.content
| i''Ex*",
          "*//:sptth*",
          "*//:ptth*",
          "*h''t''t''p*",
          "*'tp'':''/'*",
          "*$env:T\"E\"MP*",
          "*;cmd /c $?",
          "*s''t''a''r*",
          "*$*=Get-Content*AppData*.SubString(*$*",
          "*=cat *AppData*.substring(*);*$*",
          "*-join'';*
| powershell*",
          "*.Content;sleep *
| powershell*",
          "*h\''t\''tp:\''*",
          "*-e aQB3AHIAIABp*",
          "*iwr *https*).Content*",
          "*$env:computername*http*",
          "*;InVoKe-ExpRESsIoN $COntent.CONTENt;*",
          "*WebClient*example.com*",
          "*=iwr $*;iex $*",
          "*gc *:*
| sc *",
          "*gci *-Recurse*start*",
          "*Invoke-WebRequest*Start-Process*Hidden*",
          "*Invoke-WebRequest*msiexec*"
        ) or

      (process.command_line regex~ """.*p\"?o\"?w\"?e\"?r\"?s\"?h\"?e\"?l\"?l.*""" and not process.command_line : "*powershell*") or

      (process.args: "bypass" and process.args : "hidden" and process.command_line : "*start-process*appdata*") or

      (process.args : "-c" and process.args : "&{'*") or

      (process.args : "-Outfile" and process.args : "Start*") or 
      
      (process.args : "-bxor" and process.args : "0x*") or 

      process.args : "$*$*;set-alias" or

      (process.command_line : ("*-encodedCommand*", "*Invoke-webrequest*", "*WebClient*", "*Reflection.Assembly*") and
       (process.parent.name : ("explorer.exe", "python*.exe") or
        (process.parent.name : "cmd.exe" and
         descendant of [process where event.action == "start" and process.name : ("explorer.exe", "python*.exe")])))
     )

Field Validations

Loading…

Comments (0)

Loading comments...