Suspicious Communication App Child Process

Last updated 9 days ago on 2025-01-22
Created a year ago on 2023-08-04

About

Identifies suspicious child processes of communications apps, which can indicate a potential masquerading as the communication app or the exploitation of a vulnerability on the application causing it to execute code.
Tags
Domain: EndpointOS: WindowsUse Case: Threat DetectionTactic: Defense EvasionTactic: PersistenceData Source: Elastic DefendLanguage: eql
Severity
medium
Risk Score
47
MITRE ATT&CK™

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

Persistence (TA0003)(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
logs-endpoint.events.process-*
Related Integrations

endpoint(opens in a new tab or window)

Query
process where host.os.type == "windows" and event.type == "start" and
  (
    /* Slack */
    (process.parent.name : "slack.exe" and not
      (
        (
          process.executable : (
            "?:\\Program Files\\*",
            "?:\\Program Files (x86)\\*",
            "?:\\Users\\*\\AppData\\Local\\Google\\Chrome\\Application\\chrome.exe",
            "?:\\Users\\*\\AppData\\Local\\Island\\Island\\Application\\Island.exe",
            "?:\\Users\\*\\AppData\\Roaming\\Zoom\\bin*\\Zoom.exe",
            "?:\\Windows\\System32\\rundll32.exe",
            "?:\\Users\\*\\AppData\\Local\\Mozilla Firefox\\firefox.exe",
            "?:\\Windows\\System32\\notepad.exe",
            "?:\\Windows\\System32\\WerFault.exe",
            "?:\\Windows\\SysWOW64\\WerFault.exe",
            "?:\\Users\\*\\AppData\\Local\\Programs\\Opera\\opera.exe"
          ) and process.code_signature.trusted == true
        ) or
        (
          process.code_signature.subject_name : (
            "Slack Technologies, Inc.",
            "Slack Technologies, LLC"
          ) and process.code_signature.trusted == true
        ) or
        (
          (process.name : "powershell.exe" and process.command_line : "powershell.exe -c Invoke-WebRequest -Uri https://slackb.com/*") or
          (process.name : "cmd.exe" and process.command_line : "C:\\WINDOWS\\system32\\cmd.exe /d /s /c \"%windir%\\System32\\rundll32.exe User32.dll,SetFocus 0\"")
        )
      )
    ) or

    /* WebEx */
    (process.parent.name : ("CiscoCollabHost.exe", "WebexHost.exe") and not
      (
        (
          process.executable : (
            "?:\\Program Files\\*",
            "?:\\Program Files (x86)\\*",
            "?:\\Windows\\System32\\WerFault.exe",
            "?:\\Windows\\SysWOW64\\WerFault.exe",
            "?:\\Users\\*\\AppData\\Local\\Google\\Chrome\\Application\\chrome.exe",
            "?:\\Users\\*\\AppData\\Local\\Mozilla Firefox\\firefox.exe",
            "?:\\Users\\*\\AppData\\Local\\Programs\\Opera\\opera.exe"
          ) and process.code_signature.trusted == true
        ) or
        (
          process.code_signature.subject_name : (
            "Cisco Systems, Inc.",
            "Cisco WebEx LLC",
            "Cisco Systems Inc."
          ) and process.code_signature.trusted == true
        )
      )
    ) or

    /* Teams */
    (process.parent.name : "Teams.exe" and not
      (
        (
          process.executable : (
            "?:\\Program Files\\*",
            "?:\\Program Files (x86)\\*",
            "?:\\Windows\\System32\\WerFault.exe",
            "?:\\Windows\\SysWOW64\\WerFault.exe",
            "?:\\Windows\\BrowserCore\\BrowserCore.exe",
            "?:\\Users\\*\\AppData\\Local\\Google\\Chrome\\Application\\chrome.exe",
            "?:\\Users\\*\\AppData\\Local\\Mozilla Firefox\\firefox.exe"
          ) and process.code_signature.trusted == true
        ) or
        (
          process.code_signature.subject_name : (
            "Microsoft Corporation",
            "Microsoft 3rd Party Application Component"
          ) and process.code_signature.trusted == true
        ) or
        (
          (process.name : "taskkill.exe" and process.args : "Teams.exe")
        )
      )
    ) or

    /* Discord */
    (process.parent.name : "Discord.exe" and not
      (
        (
          process.executable : (
            "?:\\Program Files\\*",
            "?:\\Program Files (x86)\\*",
            "?:\\Users\\*\\AppData\\Local\\Google\\Chrome\\Application\\chrome.exe",
            "?:\\Windows\\System32\\reg.exe",
            "?:\\Windows\\SysWOW64\\reg.exe",
            "?:\\Windows\\System32\\WerFault.exe",
            "?:\\Windows\\SysWOW64\\WerFault.exe"
          ) and process.code_signature.trusted == true
        ) or
        (
          process.code_signature.subject_name : (
            "Discord Inc."
          ) and process.code_signature.trusted == true
        ) or
        (
          process.name : "cmd.exe" and
          (
            process.command_line : (
              "C:\\WINDOWS\\system32\\cmd.exe /d /s /c \"chcp\"",
              "C:\\WINDOWS\\system32\\cmd.exe /q /d /s /c \"C:\\Program^ Files\\NVIDIA^ Corporation\\NVSMI\\nvidia-smi.exe\""
            ) or
            process.args : (
              "C:\\WINDOWS/System32/nvidia-smi.exe",
              "C:\\WINDOWS\\System32\\nvidia-smi.exe",
              "C:\\Windows\\System32\\DriverStore\\FileRepository/*/nvidia-smi.exe*"
            )
          )
        )
      )
    ) or

    /* WhatsApp */
    (process.parent.name : "Whatsapp.exe" and not
      (
        (
          process.executable : (
            "?:\\Program Files\\*",
            "?:\\Program Files (x86)\\*",
            "?:\\Windows\\System32\\WerFault.exe",
            "?:\\Windows\\SysWOW64\\WerFault.exe",
            "?:\\Windows\\System32\\reg.exe",
            "?:\\Windows\\SysWOW64\\reg.exe"
          ) and process.code_signature.trusted == true
        ) or
        (
          process.code_signature.subject_name : (
            "WhatsApp LLC",
            "WhatsApp, Inc",
            "24803D75-212C-471A-BC57-9EF86AB91435"
          ) and process.code_signature.trusted == true
        ) or
        (
          (process.name : "cmd.exe" and process.command_line : "C:\\Windows\\system32\\cmd.exe /d /s /c \"C:\\Windows\\system32\\wbem\\wmic.exe*")
        )
      )
    ) or

    /* Zoom */
    (process.parent.name : "Zoom.exe" and not
      (
        (
          process.executable : (
            "?:\\Program Files\\*",
            "?:\\Program Files (x86)\\*",
            "?:\\Users\\*\\AppData\\Local\\Google\\Chrome\\Application\\chrome.exe",
            "?:\\Users\\*\\AppData\\Local\\Island\\Island\\Application\\Island.exe",
            "?:\\Users\\*\\AppData\\Local\\Mozilla Firefox\\firefox.exe",
            "?:\\Windows\\System32\\WerFault.exe",
            "?:\\Windows\\SysWOW64\\WerFault.exe"
          ) and process.code_signature.trusted == true
        ) or
        (
          process.code_signature.subject_name : (
            "Zoom Video Communications, Inc."
          ) and process.code_signature.trusted == true
        )
      )
    ) or

    /* Thunderbird */
    (process.parent.name : "thunderbird.exe" and not
      (
        (
          process.executable : (
            "?:\\Program Files\\*",
            "?:\\Program Files (x86)\\*",
            "?:\\Windows\\System32\\WerFault.exe",
            "?:\\Windows\\SysWOW64\\WerFault.exe",
            "?:\\Windows\\splwow64.exe"
          ) and process.code_signature.trusted == true
        ) or
        (
          process.code_signature.subject_name : (
            "Mozilla Corporation"
          ) and process.code_signature.trusted == true
        )
      )
    )
  )

Install detection rules in Elastic Security

Detect Suspicious Communication App Child Process 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).