File Creation, Execution and Self-Deletion in Suspicious Directory

 1[metadata]
 2creation_date = "2023/08/28"
 3integration = ["endpoint"]
 4maturity = "production"
 5updated_date = "2024/05/21"
 6
 7[rule]
 8author = ["Elastic"]
 9description = """
10This rule monitors for the creation of a file, followed by its execution and self-deletion in a short timespan within a
11directory often used for malicious purposes by threat actors. This behavior is often used by malware to execute
12malicious code and delete itself to hide its tracks.
13"""
14from = "now-9m"
15index = ["logs-endpoint.events.*"]
16language = "eql"
17license = "Elastic License v2"
18name = "File Creation, Execution and Self-Deletion in Suspicious Directory"
19risk_score = 47
20rule_id = "09bc6c90-7501-494d-b015-5d988dc3f233"
21setup = """## Setup
22
23This rule requires data coming in from Elastic Defend.
24
25### Elastic Defend Integration Setup
26Elastic 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.
27
28#### Prerequisite Requirements:
29- Fleet is required for Elastic Defend.
30- To configure Fleet Server refer to the [documentation](https://www.elastic.co/guide/en/fleet/current/fleet-server.html).
31
32#### The following steps should be executed in order to add the Elastic Defend integration on a Linux System:
33- Go to the Kibana home page and click "Add integrations".
34- In the query bar, search for "Elastic Defend" and select the integration to see more details about it.
35- Click "Add Elastic Defend".
36- Configure the integration name and optionally add a description.
37- Select the type of environment you want to protect, either "Traditional Endpoints" or "Cloud Workloads".
38- 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).
39- We suggest selecting "Complete EDR (Endpoint Detection and Response)" as a configuration setting, that provides "All events; all preventions"
40- 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.
41For more details on Elastic Agent configuration settings, refer to the [helper guide](https://www.elastic.co/guide/en/fleet/8.10/agent-policy.html).
42- Click "Save and Continue".
43- 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.
44For more details on Elastic Defend refer to the [helper guide](https://www.elastic.co/guide/en/security/current/install-endpoint.html).
45"""
46severity = "medium"
47tags = [
48    "Domain: Endpoint",
49    "OS: Linux",
50    "Use Case: Threat Detection",
51    "Tactic: Execution",
52    "Data Source: Elastic Defend",
53]
54type = "eql"
55
56query = '''
57sequence by host.id, user.id with maxspan=1m
58  [file where host.os.type == "linux" and event.action == "creation" and 
59   process.name in ("curl", "wget", "fetch", "ftp", "sftp", "scp", "rsync", "ld") and 
60   file.path : ("/dev/shm/*", "/run/shm/*", "/tmp/*", "/var/tmp/*",
61     "/run/*", "/var/run/*", "/var/www/*", "/proc/*/fd/*")] by file.name
62  [process where host.os.type == "linux" and event.type == "start" and event.action == "exec" and 
63   process.parent.name in ("bash", "dash", "ash", "sh", "tcsh", "csh", "zsh", "ksh", "fish")] by process.name
64  [file where host.os.type == "linux" and event.action == "deletion" and not process.name in ("rm", "ld") and 
65   file.path : ("/dev/shm/*", "/run/shm/*", "/tmp/*", "/var/tmp/*",
66     "/run/*", "/var/run/*", "/var/www/*", "/proc/*/fd/*")] by file.name
67'''
68
69
70[[rule.threat]]
71framework = "MITRE ATT&CK"
72[[rule.threat.technique]]
73id = "T1059"
74name = "Command and Scripting Interpreter"
75reference = "https://attack.mitre.org/techniques/T1059/"
76[[rule.threat.technique.subtechnique]]
77id = "T1059.004"
78name = "Unix Shell"
79reference = "https://attack.mitre.org/techniques/T1059/004/"
80
81
82
83[rule.threat.tactic]
84id = "TA0002"
85name = "Execution"
86reference = "https://attack.mitre.org/tactics/TA0002/"