T1505.004 IIS Components
sub-techniqueEnterpriseAdversaries may install malicious components that run on Internet Information Services (IIS) web servers to establish persistence. IIS provides several mechanisms to extend the functionality of the web servers. For example, Internet Server Application Programming Interface (ISAPI) extensions and filters can be installed to examine and/or modify incoming and outgoing IIS web requests. Extensions and filters are deployed as DLL files that export three functions: <code>Get{Extension/Filter}Version</code>, <code>Http{Extension/Filter}Proc</code>, and (optionally) <code>Terminate{Extension/Filter}</code>. IIS modules may also be installed to extend IIS web servers. Adversaries may install malicious ISAPI extensions and filters to observe and/or modify traffic, execute commands on compromised machines, or proxy command and control traffic. ISAPI extensions and filters may have access to all IIS web requests and responses. For example, an adversary may abuse these mechanisms to modify HTTP responses in order to distribute malicious commands/content to previously comprised hosts. Adversaries may also install malicious IIS modules to observe and/or modify traffic. IIS 7.0 introduced modules that provide the same unrestricted access to HTTP requests and responses as ISAPI extensions and filters. IIS modules can be written as a DLL that exports <code>RegisterModule</code>, or as a.NET application that interfaces with ASP.NET APIs to access IIS HTTP requests.
platforms
Platforms this applies to.
tactics
ATT&CK tactics this technique serves.
sub-technique of
The broader entity this sits under.
mitigations
ATT&CK mitigations that reduce this.
detected by (6)
Data components that detect this.
countered by (D3FEND)
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NIST CSF 2.0 — areas of relevance (Protect / Detect)
NIST CSF 2.0 areas this most relates to (evidence-ranked).
- PR.PSPlatform Securitymoderate · backed by 8 of 22 mapped controls
- ID.RARisk Assessmentmoderate · backed by 7 of 22 mapped controls
- PR.DSData Securitymoderate · backed by 7 of 22 mapped controls
Derived from MITRE CTID (Apache-2.0) and the NIST 800-53 ↔ CSF crosswalk (public domain). Indicative relevance along the Protect/Detect axis — not a compliance assessment or coverage claim.
mitigating controls (22)
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attack patterns (1)
CAPEC attack patterns that exploit this.
software (3)
Malware and tools associated with this.
campaigns (2)
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Detected by (Sigma) (5)
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source
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