Detection: Create Remote Thread In Shell Application

Updated Date: 2024-09-30 ID: 10399c1e-f51e-11eb-b920-acde48001122 Author: Teoderick Contreras, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects suspicious process injection in command shell applications, specifically targeting cmd.exe and powershell.exe. It leverages Sysmon EventCode 8 to identify the creation of remote threads within these shell processes. This activity is significant because it is a common technique used by malware, such as IcedID, to inject malicious code and execute it within legitimate processes. If confirmed malicious, this behavior could allow an attacker to execute arbitrary code, escalate privileges, or maintain persistence within the environment, posing a severe threat to system security.

1`sysmon` EventCode=8 TargetImage IN ("*\\cmd.exe", "*\\powershell*") 
2| stats count min(_time) as firstTime max(_time) as lastTime by  TargetImage TargetProcessId SourceProcessId  EventCode StartAddress SourceImage dest 
3|rename SourceImage as process_name
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `create_remote_thread_in_shell_application_filter`

Data Source

Name Platform Sourcetype Source
Sysmon EventID 8 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
create_remote_thread_in_shell_application_filter search *
create_remote_thread_in_shell_application_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1055 Process Injection Defense Evasion
KillChainPhase.EXPLOITAITON
NistCategory.DE_CM
Cis18Value.CIS_10
APT32
APT37
APT41
APT5
Cobalt Group
Kimsuky
PLATINUM
Silence
TA2541
Turla
Wizard Spider

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Notable Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Risk Event True
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.

Known False Positives

unknown

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
process $process_name$ create a remote thread to shell app process $TargetImage$ in host $dest$ 70 70 100
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational XmlWinEventLog
Integration ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational XmlWinEventLog

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 4