Files
sigma-rules/rules/linux/impact_potential_linux_ransomware_file_encryption.toml
T
2023-10-17 19:33:07 +05:30

81 lines
4.4 KiB
TOML

[metadata]
creation_date = "2023/03/20"
integration = ["endpoint"]
maturity = "production"
min_stack_comments = "New fields added: required_fields, related_integrations, setup"
min_stack_version = "8.3.0"
updated_date = "2023/10/16"
[rule]
author = ["Elastic"]
description = """
This rule identifies a sequence of 100 file extension rename events within a set of common file paths by the same
process in a timespan of 1 second. Ransomware is a type of malware that encrypts a victim's files or systems and
demands payment (usually in cryptocurrency) in exchange for the decryption key. One important indicator of a ransomware
attack is the mass encryption of the file system, after which a new file extension is added to the file.
"""
from = "now-9m"
index = ["logs-endpoint.events.*"]
language = "eql"
license = "Elastic License v2"
name = "Suspicious File Changes Activity Detected"
note = """## Setup
This rule requires data coming in from Elastic Defend.
### Elastic Defend Integration Setup
Elastic 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.
#### Prerequisite Requirements:
- Fleet is required for Elastic Defend.
- To configure Fleet Server refer to the [documentation](https://www.elastic.co/guide/en/fleet/current/fleet-server.html).
#### The following steps should be executed in order to add the Elastic Defend integration on a Linux System:
- Go to the Kibana home page and click Add integrations.
- In the query bar, search for Elastic Defend and select the integration to see more details about it.
- Click Add Elastic Defend.
- Configure the integration name and optionally add a description.
- Select the type of environment you want to protect, either Traditional Endpoints or Cloud Workloads.
- 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).
- We suggest to select "Complete EDR (Endpoint Detection and Response)" as a configuration setting, that provides "All events; all preventions"
- 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.
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).
- Click Save and Continue.
- 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.
For more details on Elastic Defend refer to the [helper guide](https://www.elastic.co/guide/en/security/current/install-endpoint.html).
"""
risk_score = 47
rule_id = "28738f9f-7427-4d23-bc69-756708b5f624"
severity = "medium"
tags = ["Domain: Endpoint", "OS: Linux", "Use Case: Threat Detection", "Tactic: Impact", "Data Source: Elastic Defend"]
type = "eql"
query = '''
sequence by host.id, process.entity_id with maxspan=1s
[file where host.os.type == "linux" and event.type == "change" and event.action == "rename" and file.extension : "?*"
and ((process.name in ("bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish", "ash", "openssl")) or
(process.executable : ("./*", "/tmp/*", "/var/tmp/*", "/dev/shm/*", "/var/run/*", "/boot/*", "/srv/*", "/run/*"))) and
file.path : (
"/home/*/Downloads/*", "/home/*/Documents/*", "/root/*", "/bin/*", "/usr/bin/*",
"/opt/*", "/etc/*", "/var/log/*", "/var/lib/log/*", "/var/backup/*", "/var/www/*") and not ((
process.name : (
"dpkg", "yum", "dnf", "rpm", "dockerd", "go", "java", "pip*", "python*", "node", "containerd", "php", "p4d",
"conda", "chrome", "imap", "cmake", "firefox", "semanage", "semodule", "ansible-galaxy", "fc-cache", "jammy", "git",
"systemsettings", "vmis-launcher")) or file.path : "/etc/selinux/*" or (file.extension in ("qmlc", "txt")
))] with runs=25
'''
[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1486"
name = "Data Encrypted for Impact"
reference = "https://attack.mitre.org/techniques/T1486/"
[rule.threat.tactic]
id = "TA0040"
name = "Impact"
reference = "https://attack.mitre.org/tactics/TA0040/"