Detection rules › Sigma

Shai-Hulud NPM Package Malicious Exfiltration via Curl

Status
experimental
Severity
high
Log source
product linux, category process_creation
Author
Swachchhanda Shrawan Poudel (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects potential Shai Hulud NPM package attack attempting to exfiltrate data via curl to external webhook sites.

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Shai-Hulud NPM Package Malicious Exfiltration via Curl
id: efd2eb09-b72e-4a61-8dc7-b1382a1e8983
status: experimental
description: Detects potential Shai Hulud NPM package attack attempting to exfiltrate data via curl to external webhook sites.
references:
    - https://www.getsafety.com/blog-posts/shai-hulud-npm-attack
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-09-24
tags:
    - attack.exfiltration
    - attack.t1041
    - attack.collection
    - attack.t1005
    - detection.emerging-threats
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|endswith: '/curl'
        CommandLine|contains|all:
            - 'curl'
            - '-d'
            - 'webhook.site/bb8ca5f6-4175-45d2-b042-fc9ebb8170b7'
    condition: selection
falsepositives:
    - Unlikely
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    Image|endswith: '/curl'
    CommandLine|contains|all:
        - 'curl'
        - '-d'
        - 'webhook.site/bb8ca5f6-4175-45d2-b042-fc9ebb8170b7'

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
CommandLinematch
  • -d
  • curl
  • webhook.site/bb8ca5f6-4175-45d2-b042-fc9ebb8170b7
Imageends_with
  • /curl