Windows PowerShell Disable HTTP Logging

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Description

The following analytic detects the use of get-WebConfigurationProperty and Set-ItemProperty commands in PowerShell to disable HTTP logging on Windows systems. This detection leverages PowerShell Script Block Logging, specifically looking for script blocks that reference HTTP logging properties and attempt to set them to "false" or "dontLog". Disabling HTTP logging is significant as it can be used by adversaries to cover their tracks and delete logs, hindering forensic investigations. If confirmed malicious, this activity could allow attackers to evade detection and persist in the environment undetected.

• Type: TTP
• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
• Datamodel: Web
• Last Updated: 2024-05-05
• Author: Michael Haag, Splunk
• ID: 27958de0-2857-43ca-9d4c-b255cf59dcab

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1562	Impair Defenses	Defense Evasion

T1562.002

Disable Windows Event Logging

Defense Evasion

T1505

Server Software Component

Persistence

T1505.004

IIS Components

Persistence

Kill Chain Phase

• Exploitation
• Installation

NIST

• DE.CM

CIS20

• CIS 10

CVE

Search

`powershell` EventCode=4104 ScriptBlockText IN("*get-WebConfigurationProperty*","*Set-ItemProperty*") AND ScriptBlockText IN ("*httpLogging*","*Logfile.enabled*") AND ScriptBlockText IN ("*dontLog*", "*false*")   
| stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer user_id 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_powershell_disable_http_logging_filter`

Macros

The SPL above uses the following Macros:

• powershell
• security_content_ctime

windows_powershell_disable_http_logging_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

• _time
• ScriptBlockText
• Computer
• EventCode

How To Implement

To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup here https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.

Known False Positives

It is possible administrators or scripts may run these commands, filtering may be required.

Associated Analytic Story

• IIS Components
• Windows Defense Evasion Tactics

RBA

Risk Score	Impact	Confidence	Message
64.0	80	80	A PowerShell Cmdlet related to disable or modifying a IIS HTTP logging has occurred on $Computer$.

The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

• https://www.microsoft.com/en-us/security/blog/2022/12/12/iis-modules-the-evolution-of-web-shells-and-how-to-detect-them/
• https://www.crowdstrike.com/wp-content/uploads/2022/05/crowdstrike-iceapple-a-novel-internet-information-services-post-exploitation-framework-1.pdf
• https://unit42.paloaltonetworks.com/unit42-oilrig-uses-rgdoor-iis-backdoor-targets-middle-east/
• https://www.secureworks.com/research/bronze-union

Test Dataset

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

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