ThreatsDay Briefing: Critical Firewall Flaws, Malware-as-a-Service, and the Collapse of Trusted Channel Defense

---
title: PDF Reader Spawning Script Interpreter
description: Detects Adobe Acrobat or Microsoft Edge PDF handler spawning suspicious child processes like cmd, powershell, or mshta, indicative of weaponized PDF execution.
status: experimental
date: 2026/10/27
author: Security Arsenal
references:
  - https://attack.mitre.org/techniques/T1204/002/
  - https://attack.mitre.org/techniques/T1059/
logsource:
  category: process_creation
  product: windows
detection:
  selection_parent:
    ParentImage|endswith:
      - '\AcroRd32.exe'
      - '\Acrobat.exe'
      - '\msedge.exe'
      - '\msedgewebview2.exe'
  selection_child:
    Image|endswith:
      - '\cmd.exe'
      - '\powershell.exe'
      - '\pwsh.exe'
      - '\mshta.exe'
      - '\rundll32.exe'
      - '\wscript.exe'
      - '\cscript.exe'
  condition: selection_parent and selection_child
falsepositives:
  - Legitimate PDF forms with embedded scripts (rare)
  - Enterprise document management systems
level: high
---
title: Firewall or Edge Device Suspicious Process Execution
description: Detects execution of shell commands or script interpreters from firewall/VPN directories or via unexpected binaries, common in edge device exploitation.
status: experimental
date: 2026/10/27
author: Security Arsenal
references:
  - https://attack.mitre.org/techniques/T1505/003/
  - https://attack.mitre.org/techniques/T1059/004/
logsource:
  category: process_creation
  product: windows
detection:
  selection_paths:
    Image|startswith:
      - 'C:\Program Files\Common Files\VPN'
      - 'C:\Program Files\Firewall'
      - 'C:\Windows\Temp\'
      - 'C:\Users\Public\'
  selection_commands:
    CommandLine|contains:
      - 'whoami'
      - 'ipconfig'
      - 'net user'
      - 'powershell -enc'
      - 'certutil -urlcache'
  condition: selection_paths and selection_commands
falsepositives:
  - Legitimate admin scripts running from temp folders
level: medium
---
title: Suspicious Browser Extension Token Access
description: Detects browser processes accessing sensitive cookie or token storage files, indicative of token theft attempts.
status: experimental
date: 2026/10/27
author: Security Arsenal
references:
  - https://attack.mitre.org/techniques/T1539/
logsource:
  category: file_event
  product: windows
detection:
  selection_files:
    TargetFilename|endswith:
      - '\Cookies'
      - '\Cookies-journal'
      - '\Login Data'
      - '\Local State'
  selection_access:
    Image|endswith:
      - '\chrome.exe'
      - '\msedge.exe'
      - '\firefox.exe'
  filter_known_paths:
    TargetFilename|startswith:
      - 'C:\Users\*\AppData\Local\Google\Chrome\User Data\Default\Network\Cookies'
      - 'C:\Users\*\AppData\Local\Microsoft\Edge\User Data\Default\Network\Cookies'
  condition: selection_files and selection_access and not filter_known_paths
falsepositives:
  - Browser sync processes
  - Password managers
level: medium

// Hunt for PDF readers spawning suspicious child processes
DeviceProcessEvents
| where TimeGenerated > ago(7d)
| where InitiatingProcessFileName in~ ("AcroRd32.exe", "Acrobat.exe", "msedge.exe", "msedgewebview2.exe")
| where FileName in~ ("cmd.exe", "powershell.exe", "pwsh.exe", "mshta.exe", "rundll32.exe", "wscript.exe", "cscript.exe")
| project TimeGenerated, DeviceName, InitiatingProcessFileName, InitiatingProcessCommandLine, FileName, ProcessCommandLine, AccountName
| order by TimeGenerated desc

// Hunt for potential token theft via browser local storage access
DeviceFileEvents
| where TimeGenerated > ago(7d)
| where FolderPath has_any ("Cookies", "Login Data", "Local State")
| where InitiatingProcessFileName in~ ("chrome.exe", "msedge.exe", "firefox.exe")
| where not(FolderPath has "Network\Cookies") // Filter standard cookie paths
| project TimeGenerated, DeviceName, InitiatingProcessFileName, FolderPath, FileName, SHA256
| order by TimeGenerated desc

-- Hunt for suspicious processes and persistence
SELECT Pid, Name, CommandLine, Exe, Username, CreateTime, 
       parent.Name as ParentName, parent.CommandLine as ParentCommandLine
FROM pslist()
WHERE (CommandLine =~ 'powershell|cmd|mshta|rundll32' 
       AND ParentName =~ 'AcroRd32|Acrobat|msedge')
   OR Exe =~ 'Temp|Public|AppData\\Local\\Temp'
ORDER BY CreateTime DESC

-- Check for recent run key modifications (persistence)
SELECT Name, 
       "Key" as KeyPath, 
       "Value" as ValueData, 
       Mtime
FROM glob(globs='HKLM\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Run\\*', 
          accessor='registry')
WHERE Mtime > ago(7 * 24 * 3600) -- Last 7 days
ORDER BY Mtime DESC

# ThreatsDay Defensive Script: PDF Hardening and Edge Audit
# Run as Administrator

Write-Host "[+] Starting Security Arsenal ThreatsDay Hardening Script..." -ForegroundColor Cyan

# 1. Harden Adobe Acrobat/Reader: Disable JavaScript (Common PDF attack vector)
$AdobeVersions = @("DC", "2020", "2017", "XI")
foreach ($Version in $AdobeVersions) {
    $RegPath = "HKLM:\SOFTWARE\Policies\Adobe\Adobe Acrobat\$Version\FeatureLockDown"
    if (Test-Path $RegPath) {
        Set-ItemProperty -Path $RegPath -Name "bDisableJavaScript" -Value 1 -ErrorAction SilentlyContinue
        Write-Host "[+] Disabled JavaScript for Adobe Acrobat $Version" -ForegroundColor Green
    }
}

# 2. Audit Edge Device Exposure (Firewall/VPN Management Ports)
$RiskyPorts = @(22, 23, 443, 8443, 10443, 4443, 8080, 8000, 10000)
$ListeningPorts = Get-NetTCPConnection -State Listen | Where-Object { $RiskyPorts -contains $_.LocalPort }

if ($ListeningPorts) {
    Write-Host "[!] WARNING: Management ports detected listening:" -ForegroundColor Yellow
    $ListeningPorts | Select-Object LocalAddress, LocalPort, OwningProcess | Format-Table
    Write-Host "    Recommendation: Restrict these to management VLANs only." -ForegroundColor Yellow
} else {
    Write-Host "[+] No common high-risk management ports detected." -ForegroundColor Green
}

# 3. Detect Potential Token Theft (Browser Data Access)
$SuspiciousAccess = Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4663} -MaxEvents 1000 -ErrorAction SilentlyContinue | 
    Where-Object { $_.Message -match 'Cookies|Login Data|Local State' -and $_.Message -notmatch 'Network\\Cookies' }

if ($SuspiciousAccess) {
    Write-Host "[!] ALERT: Suspicious access to browser credential stores detected!" -ForegroundColor Red
    $SuspiciousAccess | Select-Object TimeCreated, Message | Format-List
    Write-Host "    Action: Isolate host and investigate for infostealer malware." -ForegroundColor Red
} else {
    Write-Host "[+] No anomalous browser credential store access detected." -ForegroundColor Green
}

# 4. Check for recent process execution from Temp directories (common malware dropper)
$TempProcesses = Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4688} -MaxEvents 500 -ErrorAction SilentlyContinue | 
    Where-Object { $_.Message -match 'C:\\Users\\.*\\AppData\\Local\\Temp\\' -or $_.Message -match 'C:\\Windows\\Temp\\' }

if ($TempProcesses) {
    Write-Host "[!] WARNING: Processes executed from Temp directories detected:" -ForegroundColor Yellow
    $TempProcesses | Select-Object TimeCreated, Message | Format-Table -First 10
    Write-Host "    Review these for potential malware droppers." -ForegroundColor Yellow
}

Write-Host "[+] Script Complete. Review findings above." -ForegroundColor Cyan