Suspicious ArcSOC.exe Child Process

SIGMA detection rule by Micah Babinski · NOASSERTION

Detects script interpreters, command-line tools, and similar suspicious child processes of ArcSOC.exe. ArcSOC.exe is the process name which hosts ArcGIS Server REST services. If an attacker compromises an ArcGIS Server system and uploads a malicious Server Object Extension (SOE), they can send crafted requests to the corresponding service endpoint and remotely execute code from the ArcSOC.exe process.

title: Suspicious ArcSOC.exe Child Process
id: 8e95e73e-ba02-4a87-b4d7-0929b8053038
status: experimental
description: |
    This rule detects script interpreters, command-line tools, and similar suspicious child processes of ArcSOC.exe. 
    ArcSOC.exe is the process name which hosts ArcGIS Server REST services. If an attacker compromises an ArcGIS 
    Server system and uploads a malicious Server Object Extension (SOE), they can send crafted requests to the corresponding 
    service endpoint and remotely execute code from the ArcSOC.exe process.
references:
    - https://reliaquest.com/blog/threat-spotlight-inside-flax-typhoons-arcgis-compromise/
    - https://enterprise.arcgis.com/en/server/12.0/administer/windows/inside-an-arcgis-server-site.htm
author: Micah Babinski
date: 2025-11-25
tags:
    - attack.execution
    - attack.t1059
    - attack.t1203
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\ArcSOC.exe'
        Image|endswith:
            - '\rundll32.exe'
            - '\regsvr32.exe'
            - '\wscript.exe'
            - '\cscript.exe'
            - '\powershell.exe'
            - '\cmd.exe'
            - '\mshta.exe'
    filter_cmd:
        Image|endswith: '\cmd.exe'
        CommandLine: 'cmd.exe /c "ver"'
    filter_werfault:
        Image|endswith: '\werfault.exe'
    filter_esri_report_writer:
        Image|endswith: '\ESRIErrorReportWriter.exe'
    condition: selection and not 1 of filter_*
falsepositives:
    - Unknown
level: low

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

df8a9d05-aa4a-4d15-b908-b8919790a44d

Propose edits, view related rules, and engage with the community through comments.

Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

Rejected pattern present

[[ reason ]]

What does this mean?

Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

[[ reason ]]

What do these messages mean?

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

[[ currentRule.title ]]

Community Discussion