Onyx Sleet APT File Creation Indicators

Status: test
Severity: high
Log source: category file_event, product windows
Author: Nasreddine Bencherchali (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects file creation activity that is related to Onyx Sleet APT activity

Known false positives

Unlikely

MITRE ATT&CK coverage

Tactic	Techniques
Execution	No specific technique

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 11: FileCreate

Rule body

title: Onyx Sleet APT File Creation Indicators
id: 2fef4fd9-7206-40d1-b4f5-ad6441d0cd9b
status: test
description: Detects file creation activity that is related to Onyx Sleet APT activity
references:
    - https://www.microsoft.com/en-us/security/blog/2023/10/18/multiple-north-korean-threat-actors-exploiting-the-teamcity-cve-2023-42793-vulnerability/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-10-24
tags:
    - attack.execution
    - detection.emerging-threats
logsource:
    category: file_event
    product: windows
detection:
    selection:
        TargetFilename|endswith: ':\Windows\ADFS\bg\inetmgr.exe'
    condition: selection
falsepositives:
    - Unlikely
level: high

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    TargetFilename|endswith: ':\Windows\ADFS\bg\inetmgr.exe'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`TargetFilename`	ends_with	`:\Windows\ADFS\bg\inetmgr.exe`	`field:"TargetFilename" kind:ends_with value:":\Windows\ADFS\bg\inetmgr.exe"`

Onyx Sleet APT File Creation Indicators

Known false positives

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Stage 0: condition

Stage 1: selection

Indicators

Stage 0: `condition`

Stage 1: `selection`