sigma-rules/rules/windows/command_and_control_velociraptor_shell_execution.toml

[metadata]
creation_date = "2026/03/18"
integration = ["endpoint", "windows", "sentinel_one_cloud_funnel", "m365_defender", "system", "crowdstrike"]
maturity = "production"
updated_date = "2026/04/07"

[rule]
author = ["Elastic"]
description = """
Detects shell executions (cmd, PowerShell, rundll32) spawned by Velociraptor. Threat actors have been observed
installing Velociraptor to execute shell commands on compromised systems, blending in with legitimate system processes.
"""
from = "now-9m"
index = [
    "endgame-*",
    "logs-crowdstrike.fdr*",
    "logs-endpoint.events.process-*",
    "logs-m365_defender.event-*",
    "logs-sentinel_one_cloud_funnel.*",
    "logs-system.security*",
    "logs-windows.sysmon_operational-*",
    "winlogbeat-*",
]
language = "eql"
license = "Elastic License v2"
name = "Suspicious Shell Execution via Velociraptor"
note = """## Triage and analysis

### Investigating Suspicious Shell Execution via Velociraptor

Velociraptor is a legitimate endpoint visibility and response tool. Threat actors have been observed deploying it on compromised systems to run shell commands (cmd, PowerShell, rundll32), making their activity look like normal Velociraptor-collector behavior.

### Possible investigation steps

- Confirm the parent process name matches a Velociraptor binary (e.g. velociraptor.exe, Velociraptor.exe) and the child is cmd.exe, powershell.exe, or rundll32.exe.
- Review the child process command line for suspicious or interactive commands (e.g. download, lateral movement, credential access) versus known Velociraptor artifact scripts (Get-LocalGroupMember, Get-Date, registry queries, Velociraptor Tools module).
- Identify how Velociraptor was installed (dropped by another process, scheduled task, service); correlate with earlier process or file events on the host.
- Check whether the Velociraptor executable path and code signature are expected (e.g. Program Files vs. temp or user writable); unauthorized installs are often from non-standard paths.
- Correlate with other alerts for the same host or user (initial access, persistence, C2) to determine if this is abuse vs. legitimate IR/DFIR use.

### False positive analysis

- Legitimate Velociraptor artifacts that run Get-LocalGroupMember, Get-Date, registry Run key checks, or Velociraptor Tools PowerShell module are excluded by the rule; remaining FPs may be custom artifacts. Allowlist by command-line pattern or host if you use Velociraptor for authorized IR and see known-good artifacts.

### Response and remediation

- If abuse is confirmed: isolate the host, terminate the Velociraptor and child shell processes, and remove the Velociraptor installation (binary, service, config).
- Determine how Velociraptor was deployed and close the initial access vector; rotate credentials for affected accounts.
- If the deployment was authorized (IR/DFIR), document and tune the rule or add an exception to reduce noise.
"""
references = [
    "https://www.huntress.com/blog/active-exploitation-solarwinds-web-help-desk-cve-2025-26399",
    "https://attack.mitre.org/techniques/T1219/",
]
risk_score = 47
rule_id = "9aeca498-1e3d-4496-9e12-6ef40047eb23"
severity = "medium"
tags = [
    "Domain: Endpoint",
    "OS: Windows",
    "Use Case: Threat Detection",
    "Tactic: Command and Control",
    "Tactic: Execution",
    "Tactic: Defense Evasion",
    "Resources: Investigation Guide",
    "Data Source: Elastic Defend",
    "Data Source: Sysmon",
    "Data Source: SentinelOne",
    "Data Source: Microsoft Defender XDR",
    "Data Source: Crowdstrike",
    "Data Source: Elastic Endgame", 
    "Data Source: Windows Security Event Logs"
]
timestamp_override = "event.ingested"
type = "eql"

query = '''
process where host.os.type == "windows" and event.type == "start" and process.command_line != null and
 process.parent.name : "velociraptor.exe" and
 process.name : ("cmd.exe", "powershell.exe", "rundll32.exe") and
 not (process.name : "powershell.exe" and process.command_line : "*RwBlAHQALQBMAG8AYwBhAGwARwByAG8AdQBwAE0AZQBtAGIAZQBy*") and
 not (process.name : "powershell.exe" and process.command_line : "*RwBlAHQALQBEAGEAdABl*" and process.command_line : "*-Format*") and
 not (process.name : "cmd.exe" and process.command_line : "*start*127.0.0.1:8889*") and
 not (process.name : "powershell.exe" and process.command_line : "*RwBlAHQALQBJAHQAZQBt*" and process.command_line : "*UgBlAGcAaQBzAHQAcgB5*" and process.command_line : "*UgB1AG4A*") and
 not (process.name : "powershell.exe" and
      process.args : ("RwBlAHQALQ*", "UgBlAG0AbwB2AGUALQBJAHQAZQBtACA*", "C:\\Program Files\\Velociraptor\\thor.db",
                      "import-module \"C:\\Program Files\\Velociraptor\\Tools\\*"))
'''


[[rule.threat]]
framework = "MITRE ATT&CK"

[[rule.threat.technique]]
id = "T1219"
name = "Remote Access Tools"
reference = "https://attack.mitre.org/techniques/T1219/"

[[rule.threat.technique.subtechnique]]
id = "T1219.002"
name = "Remote Desktop Software"
reference = "https://attack.mitre.org/techniques/T1219/002/"

[rule.threat.tactic]
id = "TA0011"
name = "Command and Control"
reference = "https://attack.mitre.org/tactics/TA0011/"

[[rule.threat]]
framework = "MITRE ATT&CK"

[[rule.threat.technique]]
id = "T1218"
name = "System Binary Proxy Execution"
reference = "https://attack.mitre.org/techniques/T1218/"

[[rule.threat.technique.subtechnique]]
id = "T1218.011"
name = "Rundll32"
reference = "https://attack.mitre.org/techniques/T1218/011/"

[rule.threat.tactic]
id = "TA0005"
name = "Defense Evasion"
reference = "https://attack.mitre.org/tactics/TA0005/"

[[rule.threat]]
framework = "MITRE ATT&CK"

[[rule.threat.technique]]
id = "T1059"
name = "Command and Scripting Interpreter"
reference = "https://attack.mitre.org/techniques/T1059/"

[[rule.threat.technique.subtechnique]]
id = "T1059.001"
name = "PowerShell"
reference = "https://attack.mitre.org/techniques/T1059/001/"

[[rule.threat.technique.subtechnique]]
id = "T1059.003"
name = "Windows Command Shell"
reference = "https://attack.mitre.org/techniques/T1059/003/"

[rule.threat.tactic]
id = "TA0002"
name = "Execution"
reference = "https://attack.mitre.org/tactics/TA0002/"