[metadata]
creation_date = "2024/12/16"
integration = ["endpoint"]
maturity = "production"
updated_date = "2024/12/16"

[rule]
author = ["Elastic"]
description = """
This rule detects the usage of `curl` or `wget` to download the source code of a Pluggable Authentication Module (PAM)
shared object file. Attackers may download the source code of a PAM shared object file to create a backdoor in the
authentication process.
"""
false_positives = [
    "Trusted system module updates or allowed Pluggable Authentication Module (PAM) daemon configuration changes.",
]
from = "now-9m"
index = ["logs-endpoint.events.process*", "endgame-*"]
language = "eql"
license = "Elastic License v2"
name = "Pluggable Authentication Module (PAM) Source Download"
references = [
    "https://github.com/zephrax/linux-pam-backdoor",
    "https://github.com/eurialo/pambd",
    "http://0x90909090.blogspot.com/2016/06/creating-backdoor-in-pam-in-5-line-of.html",
    "https://www.trendmicro.com/en_us/research/19/i/skidmap-linux-malware-uses-rootkit-capabilities-to-hide-cryptocurrency-mining-payload.html",
]
risk_score = 21
rule_id = "53ef31ea-1f8a-493b-9614-df23d8277232"
severity = "low"
tags = [
    "Domain: Endpoint",
    "OS: Linux",
    "Use Case: Threat Detection",
    "Tactic: Credential Access",
    "Tactic: Persistence",
    "Data Source: Elastic Defend",
    "Data Source: Elastic Endgame",
]
timestamp_override = "event.ingested"
type = "eql"
query = '''
process where host.os.type == "linux" and event.type == "start" and event.action in ("exec", "exec_event") and
process.name in ("curl", "wget") and
process.args like~ "https://github.com/linux-pam/linux-pam/releases/download/v*/Linux-PAM-*.tar.xz"
'''

[[rule.threat]]
framework = "MITRE ATT&CK"

[[rule.threat.technique]]
id = "T1543"
name = "Create or Modify System Process"
reference = "https://attack.mitre.org/techniques/T1543/"

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

[[rule.threat]]
framework = "MITRE ATT&CK"

[[rule.threat.technique]]
id = "T1556"
name = "Modify Authentication Process"
reference = "https://attack.mitre.org/techniques/T1556/"

[rule.threat.tactic]
id = "TA0006"
name = "Credential Access"
reference = "https://attack.mitre.org/tactics/TA0006/"