mirror of
https://github.com/splunk/security_content
synced 2026-06-08 17:32:49 +00:00
patel-bhavin
72 lines
2.8 KiB
YAML
72 lines
2.8 KiB
YAML
name: Excessive number of taskhost processes
|
|
id: f443dac2-c7cf-11eb-ab51-acde48001122
|
|
version: 1
|
|
date: '2021-06-07'
|
|
author: Michael Hart
|
|
type: Anomaly
|
|
datamodel:
|
|
- Endpoint
|
|
description: This detection targets behaviors observed in post exploit kits like Meterpreter
|
|
and Koadic that are run in memory. We have observed that these tools must invoke
|
|
an excessive number of taskhost.exe and taskhostex.exe processes to complete various
|
|
actions (discovery, lateral movement, etc.). It is extremely uncommon in the course
|
|
of normal operations to see so many distinct taskhost and taskhostex processes running
|
|
concurrently in a short time frame.
|
|
search: '| tstats `security_content_summariesonly` values(Processes.process_id) as
|
|
process_ids min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
|
|
WHERE Processes.process_name = "taskhost.exe" OR Processes.process_name = "taskhostex.exe"
|
|
BY Processes.dest Processes.process_name _time span=1h | `drop_dm_object_name(Processes)`
|
|
| eval pid_count=mvcount(process_ids) | eval taskhost_count_=if(process_name ==
|
|
"taskhost.exe", pid_count, 0) | eval taskhostex_count_=if(process_name == "taskhostex.exe",
|
|
pid_count, 0) | stats sum(taskhost_count_) as taskhost_count, sum(taskhostex_count_)
|
|
as taskhostex_count by _time, dest, firstTime, lastTime | where taskhost_count >
|
|
10 and taskhostex_count > 10 | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
|
|
| `excessive_number_of_taskhost_processes_filter`'
|
|
how_to_implement: To successfully implement this search you need to be ingesting events
|
|
related to processes on the endpoints that include the name of the process and process
|
|
id into the `Endpoint` datamodel in the `Processes` node.
|
|
known_false_positives: Administrators, administrative actions or certain applications
|
|
may run many instances of taskhost and taskhostex concurrently. Filter as needed.
|
|
references:
|
|
- https://attack.mitre.org/software/S0250/
|
|
tags:
|
|
analytic_story:
|
|
- Meterpreter
|
|
confidence: 70
|
|
context:
|
|
- Source:Endpoint
|
|
- Stage:Defense Evasion
|
|
dataset:
|
|
- https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1059/meterpreter/taskhost_processes/logExcessiveTaskHost.log
|
|
impact: 80
|
|
kill_chain_phases:
|
|
- Exploitation
|
|
message: An excessive amount of $process_name$ was executed on $dest$ indicative
|
|
of suspicious behavior.
|
|
mitre_attack_id:
|
|
- T1059
|
|
observable:
|
|
- name: dest
|
|
type: Hostname
|
|
role:
|
|
- Victim
|
|
- name: process_name
|
|
type: Process
|
|
role:
|
|
- Child Process
|
|
product:
|
|
- Splunk Enterprise
|
|
- Splunk Enterprise Security
|
|
- Splunk Cloud
|
|
required_fields:
|
|
- _time
|
|
- Processes.process_id
|
|
- Processes.process_name
|
|
- Processes.dest
|
|
- Processes.user
|
|
risk_score: 56
|
|
security_domain: endpoint
|
|
supported_tas:
|
|
- Splunk_TA_windows
|
|
asset_type: Endpoint
|