Sigma rule: Suspicious Use of /dev/tcp

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-e6465e6276e5, updated 2023-01-06T00:00:00.000Z.

Rule

Title
Suspicious Use of /dev/tcp
Status
test
Level
medium
Author
frack113
Date
2021-12-10
Modified
2023-01-06
File
rules/linux/builtin/lnx_susp_dev_tcp.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects suspicious command with /dev/tcp

Log source

product
linux

Detection

keywords:
    - 'cat </dev/tcp/'
    - 'exec 3<>/dev/tcp/'
    - 'echo >/dev/tcp/'
    - 'bash -i >& /dev/tcp/'
    - 'sh -i >& /dev/udp/'
    - '0<&196;exec 196<>/dev/tcp/'
    - 'exec 5<>/dev/tcp/'
    - '(sh)0>/dev/tcp/'
    - 'bash -c ''bash -i >& /dev/tcp/'
    - 'echo -e ''#!/bin/bash\nbash -i >& /dev/tcp/'
condition: keywords

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.reconnaissance

References

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

Sources and licences

  • SigmaHQ

    "Suspicious Use of /dev/tcp" by frack113 (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/linux/builtin/lnx_susp_dev_tcp.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: Suspicious Use of /dev/tcp",
entity page, dataset version ref-e6465e6276e5, updated 2023-01-06T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/6cc5fceb-9a71-4c23-aeeb-963abe0b279c (accessed 2026-11-03).
Underlying source: SigmaHQ rule 6cc5fceb-9a71-4c23-aeeb-963abe0b279c, 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.