shashank-elastic
85 lines
4.6 KiB
TOML
85 lines
4.6 KiB
TOML
[metadata]
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creation_date = "2023/03/20"
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integration = ["endpoint"]
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maturity = "production"
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min_stack_comments = "New fields added: required_fields, related_integrations, setup"
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min_stack_version = "8.3.0"
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updated_date = "2023/10/16"
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[rule]
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author = ["Elastic"]
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description = """
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This rule identifies a sequence of a mass file encryption event in conjunction with the creation of a .txt file with
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a file name containing ransomware keywords executed by the same process in a 1 second timespan. Ransomware is a type of
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malware that encrypts a victim's files or systems and demands payment (usually in cryptocurrency) in exchange for the
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decryption key. One important indicator of a ransomware attack is the mass encryption of the file system, after which a
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new file extension is added to the file.
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"""
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from = "now-9m"
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index = ["logs-endpoint.events.*"]
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language = "eql"
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license = "Elastic License v2"
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name = "Potential Linux Ransomware Note Creation Detected"
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note = """## Setup
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This rule requires data coming in from Elastic Defend.
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### Elastic Defend Integration Setup
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Elastic Defend is integrated into the Elastic Agent using Fleet. Upon configuration, the integration allows
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the Elastic Agent to monitor events on your host and send data to the Elastic Security app.
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#### Prerequisite Requirements:
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- Fleet is required for Elastic Defend.
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- To configure Fleet Server refer to the [documentation](https://www.elastic.co/guide/en/fleet/current/fleet-server.html).
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#### The following steps should be executed in order to add the Elastic Defend integration on a Linux System:
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- Go to the Kibana home page and click Add integrations.
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- In the query bar, search for Elastic Defend and select the integration to see more details about it.
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- Click Add Elastic Defend.
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- Configure the integration name and optionally add a description.
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- Select the type of environment you want to protect, either Traditional Endpoints or Cloud Workloads.
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- 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).
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- We suggest to select "Complete EDR (Endpoint Detection and Response)" as a configuration setting, that provides "All events; all preventions"
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- 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.
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For more details on Elastic Agent configuration settings, refer to the [helper guide](https://www.elastic.co/guide/en/fleet/8.10/agent-policy.html).
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- Click Save and Continue.
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- 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.
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For more details on Elastic Defend refer to the [helper guide](https://www.elastic.co/guide/en/security/current/install-endpoint.html).
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"""
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risk_score = 47
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rule_id = "c8935a8b-634a-4449-98f7-bb24d3b2c0af"
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severity = "medium"
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tags = ["Domain: Endpoint", "OS: Linux", "Use Case: Threat Detection", "Tactic: Impact", "Data Source: Elastic Defend"]
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type = "eql"
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query = '''
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sequence by host.id, process.entity_id with maxspan=1s
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[file where host.os.type == "linux" and event.type == "change" and event.action == "rename" and file.extension : "?*"
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and ((process.name in ("bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish", "ash", "openssl")) or
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(process.executable : ("./*", "/tmp/*", "/var/tmp/*", "/dev/shm/*", "/var/run/*", "/boot/*", "/srv/*", "/run/*"))) and
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file.path : (
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"/home/*/Downloads/*", "/home/*/Documents/*", "/root/*", "/bin/*", "/usr/bin/*",
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"/opt/*", "/etc/*", "/var/log/*", "/var/lib/log/*", "/var/backup/*", "/var/www/*") and not ((
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process.name : (
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"dpkg", "yum", "dnf", "rpm", "dockerd", "go", "java", "pip*", "python*", "node", "containerd", "php", "p4d",
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"conda", "chrome", "imap", "cmake", "firefox", "semanage", "semodule", "ansible-galaxy", "fc-cache", "jammy", "git",
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"systemsettings", "vmis-launcher")) or (file.path : "/etc/selinux/*") or (file.extension in ("qmlc", "txt")
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))] with runs=25
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[file where host.os.type == "linux" and event.action == "creation" and file.name : (
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"*crypt*", "*restore*", "*lock*", "*recovery*", "*data*", "*read*", "*instruction*", "*how_to*", "*ransom*"
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)]
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'''
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[[rule.threat]]
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framework = "MITRE ATT&CK"
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[[rule.threat.technique]]
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id = "T1486"
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name = "Data Encrypted for Impact"
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reference = "https://attack.mitre.org/techniques/T1486/"
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[rule.threat.tactic]
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id = "TA0040"
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name = "Impact"
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reference = "https://attack.mitre.org/tactics/TA0040/"
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