sigma-rules/rules/linux/persistence_dynamic_linker_backup.toml

[metadata]
creation_date = "2022/07/12"
maturity = "production"
updated_date = "2022/08/17"

[rule]
author = ["Elastic"]
description = """
Detects the copying of the Linux dynamic loader binary and subsequent file creation for the purpose of creating a backup copy. This technique was seen recently being utilized by Linux malware prior to patching the dynamic loader in order to inject and preload a malicious shared object file. This activity should never occur and if it does then it should be considered highly suspicious or malicious.
"""
from = "now-9m"
index = ["logs-*"]
language = "eql"
license = "Elastic License v2"
name = "Dynamic Linker Copy"
references = [
    "https://www.intezer.com/blog/incident-response/orbit-new-undetected-linux-threat/"
]
risk_score = 73
rule_id = "df6f62d9-caab-4b88-affa-044f4395a1e0"
severity = "high"
tags = ["Elastic", "Host", "Linux", "Threat Detection", "Persistence", "Orbit"]
type = "eql"

query = '''
sequence by process.entity_id with maxspan=1m
[process where event.type == "start" and process.name : ("cp", "rsync") and process.args : ("/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2", "/etc/ld.so.preload")]
[file where event.action == "creation" and file.extension == "so"]
'''

[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1574"
name = "Hijack Execution Flow"
reference = "https://attack.mitre.org/techniques/T1574/"

[[rule.threat.technique.subtechnique]]
id = "T1574.006"
name = "Dynamic Linker Hijacking"
reference = "https://attack.mitre.org/techniques/T1574/006/"

[rule.threat.tactic]
id = "TA0003"
name = "Persistence"
reference = "https://attack.mitre.org/tactics/TA0003/"