XDG-Open Command Execution

  1[metadata]
  2creation_date = "2026/07/02"
  3integration = ["endpoint", "crowdstrike", "sentinel_one_cloud_funnel", "auditd_manager"]
  4maturity = "production"
  5updated_date = "2026/07/02"
  6
  7[rule]
  8author = ["Elastic"]
  9description = """
 10This rule monitors for the execution of the xdg-open process that is typically used to open documents and
 11URLs in the user's preferred desktop application. Attackers may use this command to trick users into opening
 12malicious documents or URLs to gain access to the target system.
 13"""
 14from = "now-9m"
 15index = [
 16    "endgame-*",
 17    "logs-crowdstrike.fdr*",
 18    "logs-endpoint.events.process*",
 19    "logs-sentinel_one_cloud_funnel.*",
 20    "logs-auditd_manager.auditd-*",
 21]
 22language = "eql"
 23license = "Elastic License v2"
 24name = "XDG-Open Command Execution"
 25risk_score = 47
 26rule_id = "904023d7-8307-48bc-ad49-c454dfc2fae3"
 27setup = """## Setup
 28
 29This rule requires data coming in from Elastic Defend.
 30
 31### Elastic Defend Integration Setup
 32Elastic Defend is integrated into the Elastic Agent using Fleet. Upon configuration, the integration allows the Elastic Agent to monitor events on your host and send data to the Elastic Security app.
 33
 34#### Prerequisite Requirements:
 35- Fleet is required for Elastic Defend.
 36- To configure Fleet Server refer to the [documentation](https://www.elastic.co/guide/en/fleet/current/fleet-server.html).
 37
 38#### The following steps should be executed in order to add the Elastic Defend integration on a Linux System:
 39- Go to the Kibana home page and click "Add integrations".
 40- In the query bar, search for "Elastic Defend" and select the integration to see more details about it.
 41- Click "Add Elastic Defend".
 42- Configure the integration name and optionally add a description.
 43- Select the type of environment you want to protect, either "Traditional Endpoints" or "Cloud Workloads".
 44- Select a configuration preset. Each preset comes with different default settings for Elastic Agent, you can further customize these later by configuring the Elastic Defend integration policy. [Helper guide](https://www.elastic.co/guide/en/security/current/configure-endpoint-integration-policy.html).
 45- We suggest selecting "Complete EDR (Endpoint Detection and Response)" as a configuration setting, that provides "All events; all preventions"
 46- Enter a name for the agent policy in "New agent policy name". If other agent policies already exist, you can click the "Existing hosts" tab and select an existing policy instead.
 47For more details on Elastic Agent configuration settings, refer to the [helper guide](https://www.elastic.co/guide/en/fleet/8.10/agent-policy.html).
 48- Click "Save and Continue".
 49- To complete the integration, select "Add Elastic Agent to your hosts" and continue to the next section to install the Elastic Agent on your hosts.
 50For more details on Elastic Defend refer to the [helper guide](https://www.elastic.co/guide/en/security/current/install-endpoint.html).
 51"""
 52severity = "medium"
 53tags = [
 54    "Domain: Endpoint",
 55    "OS: Linux",
 56    "Use Case: Threat Detection",
 57    "Tactic: Execution",
 58    "Data Source: Elastic Endgame",
 59    "Data Source: Elastic Defend",
 60    "Data Source: Crowdstrike",
 61    "Data Source: SentinelOne",
 62    "Data Source: Auditd Manager",
 63]
 64timestamp_override = "event.ingested"
 65type = "eql"
 66query = '''
 67process where host.os.type == "linux" and event.type == "start" and
 68event.action in ("exec", "exec_event", "executed", "process_started", "ProcessRollup2") and (
 69  process.name == "xdg-open" or
 70  process.args in ("/bin/xdg-open", "/usr/bin/xdg-open", "/usr/local/bin/xdg-open", "xdg-open")
 71)
 72'''
 73
 74[[rule.threat]]
 75framework = "MITRE ATT&CK"
 76
 77  [rule.threat.tactic]
 78  name = "Execution"
 79  id = "TA0002"
 80  reference = "https://attack.mitre.org/tactics/TA0002/"
 81
 82  [[rule.threat.technique]]
 83  id = "T1204"
 84  name = "User Execution"
 85  reference = "https://attack.mitre.org/techniques/T1204/"
 86
 87    [[rule.threat.technique.subtechnique]]
 88    id = "T1204.001"
 89    name = "Malicious Link"
 90    reference = "https://attack.mitre.org/techniques/T1204/001/"
 91
 92    [[rule.threat.technique.subtechnique]]
 93    id = "T1204.002"
 94    name = "Malicious File"
 95    reference = "https://attack.mitre.org/techniques/T1204/002/"
 96
 97    [[rule.threat.technique.subtechnique]]
 98    id = "T1204.004"
 99    name = "Malicious Copy and Paste"
100    reference = "https://attack.mitre.org/techniques/T1204/004/"