Sigma rule: Multiple Suspicious Resp Codes Caused by Single Client

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-35f43276aa31, updated 2023-03-24T00:00:00.000Z.

Rule

Title
Multiple Suspicious Resp Codes Caused by Single Client
Status
unsupported
Level
medium
Author
Thomas Patzke
Date
2017/02/19
Modified
2023/03/24
File
unsupported/web/web_multiple_susp_resp_codes_single_source.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects possible exploitation activity or bugs in a web application

Log source

category
webserver

Detection

selection:
    sc-status:
        - 400
        - 401
        - 403
        - 500
timeframe: 10m
condition: selection | count() by clientip > 10

False positives (as the rule lists them)

  • Unstable application
  • Application that misuses the response codes

Tags

  • attack.initial_access
  • attack.t1190

MITRE ATT&CK ids this rule names

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/unsupported/web/web_multiple_susp_resp_codes_single_source.yml

Sources and licences

  • SigmaHQ

    "Multiple Suspicious Resp Codes Caused by Single Client" by Thomas Patzke (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/unsupported/web/web_multiple_susp_resp_codes_single_source.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Multiple Suspicious Resp Codes Caused by Single Client",
entity page, dataset version ref-35f43276aa31, updated 2023-03-24T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/6fdfc796-06b3-46e8-af08-58f3505318af (accessed 2026-11-03).
Underlying source: SigmaHQ rule 6fdfc796-06b3-46e8-af08-58f3505318af, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.