ARCUSMEDIA Ransomware Gang: Global Campaign Intensifies — Critical Infrastructure CVEs & Detection Logic

---
title: Potential ARCUSMEDIA Initial Access Check Point IKEv1 Exploit
id: 26c7f8a1-9b4d-4f3a-8a1d-1a2b3c4d5e6f
description: Detects potential exploitation of CVE-2026-50751 involving improper authentication in IKEv1 key exchange or abnormal VPN daemon activity.
status: experimental
date: 2026/07/14
author: Security Arsenal Research
references:
    - https://www.cisa.gov/known-exploited-vulnerabilities-catalog
logsource:
    product: firewall
definition:
    condition: selection
detection:
    selection:
        dst_port: 500
        protocol: udp
        |contains:
            - 'IKE_AUTH'
            - 'INVALID_SPI'
    filter:
        src_ip:
            - '10.0.0.0/8'
            - '192.168.0.0/16'
            - '172.16.0.0/12'
falsepositives:
    - Legitimate VPN misconfigurations
level: high
tags:
    - attack.initial_access
    - cve.2026.50751
    - detection.emerging_threats
---
title: ARCUSMEDIA ConnectWise ScreenConnect RCE Indicator
id: 9d8e7f6a-5b4c-3a2d-1e0f-9a8b7c6d5e4f
description: Detects suspicious web requests associated with CVE-2024-1708 path traversal and subsequent remote code execution attempts on ScreenConnect panels.
status: experimental
date: 2026/07/14
author: Security Arsenal Research
references:
    - https://www.cisa.gov/known-exploited-vulnerabilities-catalog
logsource:
    category: web
definition:
    condition: selection
detection:
    selection:
        cs-method: 'POST'
        c-uri|contains:
            - '/App_Extensions/'
            - '..%255c'
            - 'Bin\Web.ashx'
    filter:
        cs-user-agent|contains:
            - 'ScreenConnect'
falsepositives:
    - Vulnerability scanners
level: critical
tags:
    - attack.initial_access
    - attack.exploitation_for_client_execution
    - cve.2024.1708
    - arcusmedia
---
title: Suspicious Large Volume Data Staging Pre-Encryption
id: 1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
description: Detects potential data staging activity indicative of ransomware preparation. High volume of file copies to a single directory or unusual compression usage.
status: experimental
date: 2026/07/14
author: Security Arsenal Research
logsource:
    product: windows
    service: security
definition:
    condition: selection and not filter
detection:
    selection:
        EventID: 4656 or 4663
        ObjectType: 'File'
    filter:
        ObjectName|contains:
            - 'C:\Windows'
            - 'C:\Program Files'
        SubjectUserName:
            - 'SYSTEM'
            - 'LOCAL SERVICE'
            - 'NETWORK SERVICE'
    timeframe: 1h
    condition: selection | count() > 1000
falsepositives:
    - System backups
    - Administrative file migrations
level: high
tags:
    - attack.exfiltration
    - attack.impact
    - arcusmedia

// Hunt for ARCUSMEDIA lateral movement and staging indicators
// Looks for PsExec/WMI usage followed by rapid file modifications
let ProcessCreation = SecurityEvent
| where TimeGenerated >= ago(7d)
| where EventID == 4688
| extend ProcessName = tostring(NewProcessName), CommandLine = tostring(CommandLine)
| project TimeGenerated, Computer, Account, ProcessName, CommandLine, SubjectUserName;
let FileEvents = SecurityEvent
| where TimeGenerated >= ago(7d)
| where EventID in (4663, 4656)
| extend FileName = tostring(ObjectName)
| project TimeGenerated, Computer, Account, FileName, ObjectType;
// Correlate lateral movement tools with mass file access
ProcessCreation
| where ProcessName has "psexec" or ProcessName has "wmic.exe" or CommandLine has "Invoke-WmiMethod"
| join kind=inner (FileEvents
| where FileName has ".zip" or FileName has ".rar" or FileName has ".7z" or FileName has "\\Staging\\")
  on $left.Computer == $right.Computer, $left.SubjectUserName == $right.Account
| project TimeGenerated, Computer, SubjectUserName, ProcessName, CommandLine, FileName
| where TimeGenerated >= ago(24h)

# Rapid Response: Check for Indicators of ARCUSMEDIA Compromise
# Requires Administrator Privileges

Write-Host "[+] Starting ARCUSMEDIA Rapid Response Check..." -ForegroundColor Cyan

# 1. Check for abnormal Scheduled Tasks (Last 7 Days)
Write-Host "[1] Checking for recently created scheduled tasks..." -ForegroundColor Yellow
Get-ScheduledTask | Where-Object {$_.Date -gt (Get-Date).AddDays(-7)} | Select-Object TaskName, Author, Date, Actions | Format-Table -AutoSize

# 2. Check for abnormal RDP connections (High port usage or specific user anomalies)
Write-Host "[2] Checking recent RDP connections (Event ID 4624, Type 10)..." -ForegroundColor Yellow
Get-WinEvent -FilterHashtable @{LogName='Security'; ID=4624; StartTime=(Get-Date).AddHours(-24)} -ErrorAction SilentlyContinue |
Where-Object {$_.Message -match 'Logon Type:\s*10'} |
Select-Object TimeCreated, @{n='User';e={$_.Properties[5].Value}}, @{n='IP';e={$_.Properties[19].Value}} |
Format-Table -AutoSize

# 3. Check for Volume Shadow Copy Deletion or Modification (vssadmin)
Write-Host "[3] Checking for vssadmin manipulation attempts..." -ForegroundColor Yellow
Get-WinEvent -FilterHashtable @{LogName='Security'; ID=4688; StartTime=(Get-Date).AddDays(-1)} -ErrorAction SilentlyContinue |
Where-Object {$_.Message -match 'vssadmin.*delete' -or $_.Message -match 'vssadmin.*resize'} |
Select-Object TimeCreated, @{n='Process';e={$_.Properties[5].Value}}, @{n='CommandLine';e={$_.Properties[8].Value}}

# 4. Network Check: Established connections to non-standard ports (Potential C2)
Write-Host "[4] Checking for established connections on high ports..." -ForegroundColor Yellow
Get-NetTCPConnection -State Established | Where-Object {$_.RemotePort -gt 1024 -and $_.RemotePort -ne 443} | Select-Object LocalAddress, LocalPort, RemoteAddress, RemotePort, OwningProcess

Write-Host "[-] Check Complete. Review output for anomalies." -ForegroundColor Green


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