File Download Via Windows Defender MpCmpRun.EXE

Status: test
Severity: high
Log source: category process_creation, product windows
Author: Matthew Matchen
Source: github.com/SigmaHQ/sigma

Detects the use of Windows Defender MpCmdRun.EXE to download files

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1218` System Binary Proxy Execution
Command & Control	`T1105` Ingress Tool Transfer

Telemetry coverage

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

Rule body

title: File Download Via Windows Defender MpCmpRun.EXE
id: 46123129-1024-423e-9fae-43af4a0fa9a5
status: test
description: Detects the use of Windows Defender MpCmdRun.EXE to download files
references:
    - https://web.archive.org/web/20200903194959/https://twitter.com/djmtshepana/status/1301608169496612866
    - https://lolbas-project.github.io/lolbas/Binaries/MpCmdRun/
author: Matthew Matchen
date: 2020-09-04
modified: 2023-11-09
tags:
    - attack.stealth
    - attack.t1218
    - attack.command-and-control
    - attack.t1105
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - OriginalFileName: 'MpCmdRun.exe'
        - Image|endswith: '\MpCmdRun.exe'
        - CommandLine|contains: 'MpCmdRun.exe'
        - Description: 'Microsoft Malware Protection Command Line Utility'
    selection_cli:
        CommandLine|contains|all:
            - 'DownloadFile'
            - 'url'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: `condition`

all of selection_*

Stage 1: `selection_img`

selection_img:
    - OriginalFileName: 'MpCmdRun.exe'
    - Image|endswith: '\MpCmdRun.exe'
    - CommandLine|contains: 'MpCmdRun.exe'
    - Description: 'Microsoft Malware Protection Command Line Utility'

Stage 2: `selection_cli`

selection_cli:
    CommandLine|contains|all:
        - 'DownloadFile'
        - 'url'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CommandLine`	match	`DownloadFile` corpus 6 (sigma 4, elastic 1, chronicle 1) `MpCmdRun.exe` corpus 2 (sigma 1, chronicle 1) `url` corpus 2 (sigma 1, chronicle 1)	`field:"CommandLine" kind:match`
`Description`	eq	`Microsoft Malware Protection Command Line Utility`	`field:"Description" kind:eq value:"Microsoft Malware Protection Command Line Utility"`
`Image`	ends_with	`\MpCmdRun.exe` corpus 4 (sigma 4)	`field:"Image" kind:ends_with value:"\MpCmdRun.exe"`
`OriginalFileName`	eq	`MpCmdRun.exe` corpus 4 (sigma 2, elastic 1, splunk 1)	`field:"OriginalFileName" kind:eq value:"MpCmdRun.exe"`

File Download Via Windows Defender MpCmpRun.EXE

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Stage 0: condition

Stage 1: selection_img

Stage 2: selection_cli

Indicators

Stage 0: `condition`

Stage 1: `selection_img`

Stage 2: `selection_cli`