Renamed NetSupport RAT Execution

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

Detects the execution of a renamed "client32.exe" (NetSupport RAT) via Imphash, Product and OriginalFileName strings

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: Renamed NetSupport RAT Execution
id: 0afbd410-de03-4078-8491-f132303cb67d
status: test
description: Detects the execution of a renamed "client32.exe" (NetSupport RAT) via Imphash, Product and OriginalFileName strings
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:
        - Product|contains: 'NetSupport Remote Control'
        - OriginalFileName|contains: 'client32.exe'
        - Hashes|contains: IMPHASH=A9D50692E95B79723F3E76FCF70D023E
    filter:
        Image|endswith: '\client32.exe'
    condition: selection and not filter
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: `condition`

selection and not filter

Stage 1: `selection`

selection:
    - Product|contains: 'NetSupport Remote Control'
    - OriginalFileName|contains: 'client32.exe'
    - Hashes|contains: IMPHASH=A9D50692E95B79723F3E76FCF70D023E

Stage 2: `not filter`

filter:
    Image|endswith: '\client32.exe'

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`Image`	ends_with	`\client32.exe`	`excludes:Image` `field:"Image" value:"\client32.exe"`

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"`
`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"`