Jonhnathan
b4c84e8a40
* Update Tags * Bump updated date separately to be easy to revert if needed * Update resource_development_ml_linux_anomalous_compiler_activity.toml * Apply changes from the discussion * Update persistence_init_d_file_creation.toml * Update defense_evasion_timestomp_sysmon.toml * Update defense_evasion_application_removed_from_blocklist_in_google_workspace.toml * Update missing Tactic tags * Update unit tests to match new tags * Add missing IG tags * Delete okta_threat_detected_by_okta_threatinsight.toml * Update command_and_control_google_drive_malicious_file_download.toml * Update persistence_rc_script_creation.toml * Mass bump * Update persistence_shell_activity_by_web_server.toml * . --------- Co-authored-by: Mika Ayenson <Mika.ayenson@elastic.co> Co-authored-by: Mika Ayenson <Mikaayenson@users.noreply.github.com>
60 lines
2.0 KiB
TOML
60 lines
2.0 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 = "2023/03/20"
|
|
|
|
[rule]
|
|
author = ["Elastic"]
|
|
description = """
|
|
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. Generally, a ransomware note with contact details is dropped onto the
|
|
file system which can be used by the victim to contact the attacker. This rule identifies a
|
|
sequence of a mass file encryption event in conjunction with the creation of a .txt file with
|
|
a file name containing ransomware keywords executed by the same process in a 1 second timespan.
|
|
"""
|
|
from = "now-9m"
|
|
index = ["logs-endpoint.events.*"]
|
|
language = "eql"
|
|
license = "Elastic License v2"
|
|
name = "Potential Linux Ransomware Note Creation Detected"
|
|
risk_score = 73
|
|
rule_id = "c8935a8b-634a-4449-98f7-bb24d3b2c0af"
|
|
severity = "high"
|
|
tags = ["Domain: Endpoint", "OS: Linux", "Use Case: Threat Detection", "Tactic: Impact"]
|
|
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 != "" ] with runs=50
|
|
[ file where host.os.type == "linux" and event.action == "creation" and
|
|
file.extension == "txt" and file.name : (
|
|
"*crypt*",
|
|
"*restore*",
|
|
"*lock*",
|
|
"*recovery*",
|
|
"*data*",
|
|
"*read*",
|
|
"*instruction*",
|
|
"*how_to*",
|
|
"*ransom*"
|
|
) ] | tail 1
|
|
'''
|
|
|
|
|
|
[[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/" |