Suspicious Child Process of PaperCut Server Component

Last updated a day ago on 2026-08-28
Created a day ago on 2026-08-28

About

Detects suspicious child process execution originating from PaperCut server components, including the PaperCut NG/MF Application Server (pc-app.exe) and PaperCut Hive print job spooler (pc-printjob-spooler.exe). Active exploitation of CVE-2026-82078 and CVE-2026-81578 abuses unsafe dynamic class loading and an authentication bypass to achieve pre-authenticated remote code execution under pc-app.exe. Similar suspicious shell spawning has also been observed from PaperCut Hive's pc-printjob-spooler.exe (for example cmd.exe executing echo/test-style commands). Observed NG/MF in-the-wild activity includes discovery utilities such as whoami and tasklist; proof-of-concept exploitation has spawned unexpected Windows utilities such as charmap.exe as SYSTEM.
Tags
Domain: EndpointOS: WindowsUse Case: Threat DetectionUse Case: VulnerabilityTactic: Initial AccessTactic: ExecutionData Source: Elastic DefendData Source: Elastic EndgameData Source: SysmonData Source: Windows Security Event LogsData Source: Microsoft Defender XDRData Source: SentinelOneData Source: CrowdstrikeLanguage: eql
Severity
high
Risk Score
73
MITRE ATT&CK™

Initial Access (TA0001)(external, opens in a new tab or window)

Execution (TA0002)(external, opens in a new tab or window)

License
Elastic License v2(external, opens in a new tab or window)

Definition

Rule Type
Event Correlation Rule
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
logs-endpoint.events.process-*winlogbeat-*logs-windows.sysmon_operational-*logs-windows.forwarded*logs-system.security*endgame-*logs-m365_defender.event-*logs-sentinel_one_cloud_funnel.*logs-crowdstrike.fdr*
Related Integrations

endpoint(external, opens in a new tab or window)

windows(external, opens in a new tab or window)

system(external, opens in a new tab or window)

m365_defender(external, opens in a new tab or window)

sentinel_one_cloud_funnel(external, opens in a new tab or window)

crowdstrike(external, opens in a new tab or window)

Query
text code block:
process where host.os.type == "windows" and event.type == "start" and process.parent.name : ("pc-app.exe", "pc-printjob-spooler.exe") and ( process.name : ( "cmd.exe", "powershell.exe", "pwsh.exe", "powershell_ise.exe", "wscript.exe", "cscript.exe", "mshta.exe", "rundll32.exe", "regsvr32.exe", "bitsadmin.exe", "certutil.exe", "curl.exe", "wget.exe", "net.exe", "net1.exe", "whoami.exe", "tasklist.exe", "ipconfig.exe", "nltest.exe", "systeminfo.exe", "charmap.exe", "calc.exe", "mspaint.exe" ) or ?process.pe.original_file_name : ( "Cmd.Exe", "PowerShell.EXE", "pwsh.dll", "powershell_ise.EXE", "wscript.exe", "cscript.exe", "MSHTA.EXE", "RUNDLL32.EXE", "REGSVR32.EXE", "bitsadmin.exe", "CertUtil.exe", "curl.exe", "wget.exe", "net.exe", "net1.exe", "whoami.exe", "tasklist.exe", "ipconfig.exe", "nltest.exe", "systeminfo.exe", "charmap.exe", "CALC.EXE", "mspaint.exe" ) )

Install detection rules in Elastic Security

Detect Suspicious Child Process of PaperCut Server Component in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).