Windows IIS Components Module Failed to Load

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Description

The following analytic detects when an IIS Module DLL fails to load due to a configuration problem, identified by EventCode 2282. This detection leverages Windows Application event logs to identify repeated failures in loading IIS modules. Such failures can indicate misconfigurations or potential tampering with IIS components. If confirmed malicious, this activity could lead to service disruptions or provide an attacker with opportunities to exploit vulnerabilities within the IIS environment. Immediate investigation is required to determine the legitimacy of the failing module and to mitigate any potential security risks.

• Type: Anomaly

• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

• Last Updated: 2024-05-15
• Author: Michael Haag, Splunk
• ID: 40c2ba5b-dd6a-496b-9e6e-c9524d0be167

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1505	Server Software Component	Persistence

T1505.004

IIS Components

Persistence

Kill Chain Phase

• Installation

NIST

• DE.AE

CIS20

• CIS 10

CVE

Search

`wineventlog_application` EventCode=2282 
| stats  count min(_time) as firstTime max(_time) as lastTime by  EventCode dest Name ModuleDll 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_iis_components_module_failed_to_load_filter`

Macros

The SPL above uses the following Macros:

• security_content_ctime
• wineventlog_application

windows_iis_components_module_failed_to_load_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
• OpCode
• EventCode
• ComputerName
• Message

How To Implement

IIS must be installed and Application event logs must be collected in order to utilize this analytic.

Known False Positives

False positives will be present until all module failures are resolved or reviewed.

Associated Analytic Story

• IIS Components

RBA

Risk Score	Impact	Confidence	Message
25.0	50	50	A new IIS Module has been loaded and should be reviewed on $dest$.

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://social.technet.microsoft.com/wiki/contents/articles/21757.event-id-2282-iis-worker-process-availability.aspx
• 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
• https://github.com/redcanaryco/atomic-red-team/tree/master/atomics/T1505.004
• https://strontic.github.io/xcyclopedia/library/appcmd.exe-055B2B09409F980BF9B5A3969D01E5B2.html

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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