Potential Unauthorized Access via Wildcard Injection Detected

This rule monitors for the execution of the "chown" and "chmod" commands with command line flags that could indicate a wildcard injection attack. Linux wildcard injection is a type of security vulnerability where attackers manipulate commands or input containing wildcards (e.g., *, ?, []) to execute unintended operations or access sensitive data by tricking the system into interpreting the wildcard characters in unexpected ways.

Elastic rule (View on GitHub)

 1[metadata]
 2creation_date = "2023/07/28"
 3integration = ["endpoint", "auditd_manager"]
 4maturity = "production"
 5min_stack_comments = "New fields added: required_fields, related_integrations, setup"
 6min_stack_version = "8.3.0"
 7updated_date = "2024/03/08"
 8
 9[rule]
10author = ["Elastic"]
11description = """
12This rule monitors for the execution of the "chown" and "chmod" commands with command line flags that could indicate a
13wildcard injection attack. Linux wildcard injection is a type of security vulnerability where attackers manipulate 
14commands or input containing wildcards (e.g., *, ?, []) to execute unintended operations or access sensitive data by
15tricking the system into interpreting the wildcard characters in unexpected ways.
16"""
17from = "now-9m"
18index = ["logs-endpoint.events.*", "endgame-*", "auditbeat-*", "logs-auditd_manager.auditd-*"]
19language = "eql"
20license = "Elastic License v2"
21name = "Potential Unauthorized Access via Wildcard Injection Detected"
22references = ["https://www.exploit-db.com/papers/33930"]
23risk_score = 21
24rule_id = "4a99ac6f-9a54-4ba5-a64f-6eb65695841b"
25setup = """## Setup
26
27This rule requires data coming in from Elastic Defend.
28
29### Elastic Defend Integration Setup
30Elastic 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.
31
32#### Prerequisite Requirements:
33- Fleet is required for Elastic Defend.
34- To configure Fleet Server refer to the [documentation](https://www.elastic.co/guide/en/fleet/current/fleet-server.html).
35
36#### The following steps should be executed in order to add the Elastic Defend integration on a Linux System:
37- Go to the Kibana home page and click "Add integrations".
38- In the query bar, search for "Elastic Defend" and select the integration to see more details about it.
39- Click "Add Elastic Defend".
40- Configure the integration name and optionally add a description.
41- Select the type of environment you want to protect, either "Traditional Endpoints" or "Cloud Workloads".
42- 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).
43- We suggest selecting "Complete EDR (Endpoint Detection and Response)" as a configuration setting, that provides "All events; all preventions"
44- 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.
45For more details on Elastic Agent configuration settings, refer to the [helper guide](https://www.elastic.co/guide/en/fleet/8.10/agent-policy.html).
46- Click "Save and Continue".
47- 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.
48For more details on Elastic Defend refer to the [helper guide](https://www.elastic.co/guide/en/security/current/install-endpoint.html).
49"""
50severity = "low"
51tags = [
52        "Domain: Endpoint",
53        "OS: Linux",
54        "Use Case: Threat Detection",
55        "Tactic: Privilege Escalation",
56        "Tactic: Credential Access",
57        "Data Source: Elastic Endgame",
58        "Data Source: Elastic Defend",
59        "Data Source: Auditd Manager"
60        ]
61timestamp_override = "event.ingested"
62type = "eql"
63query = '''
64process where host.os.type == "linux" and event.type == "start" and event.action in ("exec", "exec_event", "executed", "process_started")
65 and process.name in ("chown", "chmod") and process.args == "-R" and process.args : "--reference=*"
66'''
67
68[[rule.threat]]
69framework = "MITRE ATT&CK"
70
71[[rule.threat.technique]]
72id = "T1068"
73name = "Exploitation for Privilege Escalation"
74reference = "https://attack.mitre.org/techniques/T1068/"
75
76[rule.threat.tactic]
77id = "TA0004"
78name = "Privilege Escalation"
79reference = "https://attack.mitre.org/tactics/TA0004/"
80
81[[rule.threat]]
82framework = "MITRE ATT&CK"
83
84[[rule.threat.technique]]
85id = "T1003"
86name = "OS Credential Dumping"
87reference = "https://attack.mitre.org/techniques/T1003/"
88
89[[rule.threat.technique.subtechnique]]
90id = "T1003.008"
91name = "/etc/passwd and /etc/shadow"
92reference = "https://attack.mitre.org/techniques/T1003/008/"
93
94[rule.threat.tactic]
95id = "TA0006"
96name = "Credential Access"
97reference = "https://attack.mitre.org/tactics/TA0006/"

References

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