defense_evasion_base64_encoding_or_decoding_activity.toml

[metadata]
creation_date = "2020/04/17"
deprecation_date = "2021/04/15"
maturity = "deprecated"
updated_date = "2021/04/15"

[rule]
author = ["Elastic"]
description = "Adversaries may encode/decode data in an attempt to evade detection by host- or network-based security controls."
false_positives = [
    """
    Automated tools such as Jenkins may encode or decode files as part of their normal behavior. These events can be
    filtered by the process executable or username values.
    """,
]
from = "now-9m"
index = ["auditbeat-*", "logs-endpoint.events.*"]
language = "kuery"
license = "Elastic License v2"
name = "Base64 Encoding/Decoding Activity"
risk_score = 21
rule_id = "97f22dab-84e8-409d-955e-dacd1d31670b"
severity = "low"
tags = ["Elastic", "Host", "Linux", "Threat Detection", "Defense Evasion"]
timestamp_override = "event.ingested"
type = "query"

query = '''
event.category:process and event.type:(start or process_started) and
  process.name:(base64 or base64plain or base64url or base64mime or base64pem)
'''


[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1140"
name = "Deobfuscate/Decode Files or Information"
reference = "https://attack.mitre.org/techniques/T1140/"

[[rule.threat.technique]]
id = "T1027"
name = "Obfuscated Files or Information"
reference = "https://attack.mitre.org/techniques/T1027/"


[rule.threat.tactic]
id = "TA0005"
name = "Defense Evasion"
reference = "https://attack.mitre.org/tactics/TA0005/"