Detection rules › Sigma

Webserver IIS configuration edited (SYSMON)

Status
experimental
Severity
high
Log source
product windows, category file_event
Author
mdecrevoisier
Source
github.com/mdecrevoisier/SIGMA-detection-rules

Detects scenarios where an attacker attempts to edit IIS configuration file in order to load a module.

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 11FileCreate

Rule body yaml

title: Webserver IIS configuration edited (SYSMON)
description: Detects scenarios where an attacker attempts to edit IIS configuration file in order to load a module.
requirements: requires to update SYSMON configuration to include the IIS application path.
references:
- https://www.microsoft.com/security/blog/2022/07/26/malicious-iis-extensions-quietly-open-persistent-backdoors-into-servers/
- https://docs.microsoft.com/en-us/iis/get-started/planning-your-iis-architecture/introduction-to-applicationhostconfig
tags:
- attack.persistence
- attack.t1505.004
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  category: file_event
detection:
  selection:
    EventID: 11
    TargetFilename|endswith: '\inetsrv\config\applicationHost.config'
  condition: selection
falsepositives:
- rare administrator change
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
  EventID: 11
  TargetFilename|endswith: '\inetsrv\config\applicationHost.config'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
TargetFilenameends_with
  • \inetsrv\config\applicationHost.config