Remote Access Tool - NetSupport Execution From Unusual Location

Status: test
Severity: medium
Log source: category process_creation, product windows
Author: Nasreddine Bencherchali (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects execution of client32.exe (NetSupport RAT) from an unusual location (outside of 'C:\Program Files')

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	No specific technique

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation

Rule body

title: Remote Access Tool - NetSupport Execution From Unusual Location
id: 37e8d358-6408-4853-82f4-98333fca7014
status: test
description: Detects execution of client32.exe (NetSupport RAT) from an unusual location (outside of 'C:\Program Files')
references:
    - https://redcanary.com/blog/misbehaving-rats/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-09-19
modified: 2024-11-23
tags:
    - attack.stealth
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        - Image|endswith: '\client32.exe'
        - Product|contains: 'NetSupport Remote Control'
        - OriginalFileName|contains: 'client32.exe'
        - Hashes|contains: IMPHASH=a9d50692e95b79723f3e76fcf70d023e
    filter:
        Image|startswith:
            - 'C:\Program Files\'
            - 'C:\Program Files (x86)\'
    condition: selection and not filter
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: `condition`

selection and not filter

Stage 1: `selection`

selection:
    - Image|endswith: '\client32.exe'
    - Product|contains: 'NetSupport Remote Control'
    - OriginalFileName|contains: 'client32.exe'
    - Hashes|contains: IMPHASH=a9d50692e95b79723f3e76fcf70d023e

Stage 2: `not filter`

filter:
    Image|startswith:
        - 'C:\Program Files\'
        - 'C:\Program Files (x86)\'

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`Image`	starts_with	`C:\Program Files (x86)\`	`excludes:Image` `field:"Image" value:"C:\Program Files (x86)\"`
`Image`	starts_with	`C:\Program Files\`	`excludes:Image` `field:"Image" value:"C:\Program Files\"`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Hashes`	match	`IMPHASH=a9d50692e95b79723f3e76fcf70d023e` corpus 2 (sigma 2)	`field:"Hashes" kind:match value:"IMPHASH=a9d50692e95b79723f3e76fcf70d023e"`
`Image`	ends_with	`\client32.exe`	`field:"Image" kind:ends_with value:"\client32.exe"`
`OriginalFileName`	match	`client32.exe` corpus 2 (sigma 2)	`field:"OriginalFileName" kind:match value:"client32.exe"`
`Product`	match	`NetSupport Remote Control` corpus 2 (sigma 2)	`field:"Product" kind:match value:"NetSupport Remote Control"`