Process Masquerading as Kernel Process

[rule]
description = """
This rule detects potential process masquerading as a kernel process. Attackers may leverage the `exec -a` command to
change the name of a process to mimic a kernel process, such as `kworker`, `ksoftirqd`, or `kthreadd`. When `exec` is
spawned directly, it will kill the currently running shell, and continue to run as the masqueraded process. This leads
to spawning a process with only one process argument, which is the name of a kernel thread (hence the brackets). This
technique is used by malware to hide the true identity of a process from security tools and analysts.
"""
id = "fb2c3240-4cbe-413e-be78-5427807b618b"
license = "Elastic License v2"
name = "Process Masquerading as Kernel Process"
os_list = ["linux"]
version = "1.0.4"

query = '''
process where event.type == "start" and event.action == "exec" and process.args_count == 1 and
process.command_line like "[*]" and not (
  process.executable like "/opt/splunk*" or
  process.parent.executable like "/opt/splunk*" or
  process.executable in ("/usr/local/ahnlab/v3net/bin/v3containerd", "/usr/local/ahnlab/v3net/bin/v3brokerd")
)
'''

min_endpoint_version = "7.15.0"
optional_actions = []
[[actions]]
action = "kill_process"
field = "process.entity_id"
state = 0

[[actions]]
action = "kill_process"
field = "process.parent.entity_id"
state = 0

[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1059"
name = "Command and Scripting Interpreter"
reference = "https://attack.mitre.org/techniques/T1059/"
[[threat.technique.subtechnique]]
id = "T1059.004"
name = "Unix Shell"
reference = "https://attack.mitre.org/techniques/T1059/004/"



[threat.tactic]
id = "TA0002"
name = "Execution"
reference = "https://attack.mitre.org/tactics/TA0002/"
[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1564"
name = "Hide Artifacts"
reference = "https://attack.mitre.org/techniques/T1564/"


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

[internal]
min_endpoint_version = "7.15.0"