Modification of Environment Variable via Unsigned or Untrusted Parent

 1[metadata]
 2creation_date = "2021/01/14"
 3integration = ["endpoint"]
 4maturity = "production"
 5updated_date = "2024/11/07"
 6
 7[rule]
 8author = ["Elastic"]
 9description = """
10Identifies modifications to an environment variable using the built-in launchctl command. Adversaries may execute their
11own malicious payloads by hijacking certain environment variables to load arbitrary libraries or bypass certain
12restrictions.
13"""
14from = "now-9m"
15index = ["logs-endpoint.events.*"]
16language = "kuery"
17license = "Elastic License v2"
18name = "Modification of Environment Variable via Unsigned or Untrusted Parent"
19references = [
20    "https://github.com/rapid7/metasploit-framework/blob/master//modules/post/osx/escalate/tccbypass.rb",
21]
22risk_score = 47
23rule_id = "7453e19e-3dbf-4e4e-9ae0-33d6c6ed15e1"
24setup = """## Setup
25
26This rule requires data coming in from Elastic Defend.
27
28### Elastic Defend Integration Setup
29Elastic 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.
30
31#### Prerequisite Requirements:
32- Fleet is required for Elastic Defend.
33- To configure Fleet Server refer to the [documentation](https://www.elastic.co/guide/en/fleet/current/fleet-server.html).
34
35#### The following steps should be executed in order to add the Elastic Defend integration on a macOS System:
36- Go to the Kibana home page and click "Add integrations".
37- In the query bar, search for "Elastic Defend" and select the integration to see more details about it.
38- Click "Add Elastic Defend".
39- Configure the integration name and optionally add a description.
40- Select the type of environment you want to protect, for MacOS it is recommended to select "Traditional Endpoints".
41- 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).
42- We suggest selecting "Complete EDR (Endpoint Detection and Response)" as a configuration setting, that provides "All events; all preventions"
43- 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.
44For more details on Elastic Agent configuration settings, refer to the [helper guide](https://www.elastic.co/guide/en/fleet/current/agent-policy.html).
45- Click "Save and Continue".
46- 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.
47For more details on Elastic Defend refer to the [helper guide](https://www.elastic.co/guide/en/security/current/install-endpoint.html).
48"""
49severity = "medium"
50tags = [
51    "Domain: Endpoint",
52    "OS: macOS",
53    "Use Case: Threat Detection",
54    "Tactic: Defense Evasion",
55    "Data Source: Elastic Defend",
56]
57timestamp_override = "event.ingested"
58type = "query"
59
60query = '''
61event.category:process and host.os.type:macos and event.type:start and 
62  process.name:launchctl and 
63  (process.parent.code_signature.exists : false or process.parent.code_signature.trusted : false) and
64  process.args:(setenv and not (ANT_HOME or 
65                                DBUS_LAUNCHD_SESSION_BUS_SOCKET or 
66                                EDEN_ENV or 
67                                LG_WEBOS_TV_SDK_HOME or 
68                                RUNTIME_JAVA_HOME or 
69                                WEBOS_CLI_TV or 
70                                JAVA*_HOME) and 
71                not *.vmoptions) and 
72  not process.parent.executable:("/Applications/IntelliJ IDEA CE.app/Contents/jbr/Contents/Home/lib/jspawnhelper" or 
73                                  /Applications/NoMachine.app/Contents/Frameworks/bin/nxserver.bin or 
74                                  /Applications/NoMachine.app/Contents/Frameworks/bin/nxserver.bin or 
75                                  /usr/local/bin/kr)
76'''
77
78
79[[rule.threat]]
80framework = "MITRE ATT&CK"
81[[rule.threat.technique]]
82id = "T1574"
83name = "Hijack Execution Flow"
84reference = "https://attack.mitre.org/techniques/T1574/"
85[[rule.threat.technique.subtechnique]]
86id = "T1574.007"
87name = "Path Interception by PATH Environment Variable"
88reference = "https://attack.mitre.org/techniques/T1574/007/"
89
90
91
92[rule.threat.tactic]
93id = "TA0005"
94name = "Defense Evasion"
95reference = "https://attack.mitre.org/tactics/TA0005/"