Critical Linux Kernel & PAN-OS Flaws: Detecting AI-Driven OAuth Attacks and 'Cron Job' Exploits

---
title: Potential Linux Exploitation via Curl Pipe to Shell
id: 8a4b2c1d-5e6f-4a3b-8c9d-0e1f2a3b4c5d
status: experimental
description: Detects the execution of curl or wget piping output directly to bash or sh, a common technique in supply chain poisoning and repo-side attacks. References the 'curl | sh' behavior mentioned in threat intel.
references:
  - https://thehackernews.com/2026/06/weekly-recap-new-linux-flaw-pan-os.html
author: Security Arsenal
date: 2026/06/16
tags:
  - attack.execution
  - attack.t1059.004
logsource:
  category: process_creation
  product: linux
detection:
  selection:
    CommandLine|contains:
      - 'curl | '
      - 'wget | '
      - 'curl | sh'
      - 'curl | bash'
  condition: selection
falsepositives:
  - Legitimate developer environment setup scripts
  - System administration automation
level: high
---
title: Suspicious Process Spawned by Cron Daemon
id: 9b5c3d2e-6f7a-5b4c-9d0e-1f2a3b4c5d6e
status: experimental
description: Detects unusual or high-risk child processes spawned by the cron daemon, correlating with the 'cron job with anger issues' metaphor regarding active scheduled task exploitation.
references:
  - https://thehackernews.com/2026/06/weekly-recap-new-linux-flaw-pan-os.html
author: Security Arsenal
date: 2026/06/16
tags:
  - attack.persistence
  - attack.t1053.003
logsource:
  category: process_creation
  product: linux
detection:
  selection_parent:
    ParentImage|endswith: '/cron'
    ParentImage|contains:
      - '/usr/sbin/cron'
      - '/usr/bin/cron'
  selection_child:
    Image|endswith:
      - '/sh'
      - '/bash'
      - '/python'
      - '/perl'
      - '/nc'
      - '/netcat'
  condition: all of selection_*
falsepositives:
  - Legitimate scheduled maintenance tasks
  - Log rotation scripts
level: medium
---
title: OAuth Consent to High-Risk or Unverified App
id: 0c1d2e3f-4a5b-6c7d-8e9f-0a1b2c3d4e5f
status: experimental
description: Detects users granting OAuth permissions to applications, specifically targeting AI-driven social engineering campaigns mimicking productivity tools.
references:
  - https://thehackernews.com/2026/06/weekly-recap-new-linux-flaw-pan-os.html
author: Security Arsenal
date: 2026/06/16
tags:
  - attack.initial_access
  - attack.t1078.004
logsource:
  product: azure
  service: auditlogs
detection:
  selection:
    CategoryValue: 'ApplicationManagement'
    OperationName: 'Consent to application'
  filter:
    TargetResources|contains:
      - 'microsoft.com'
      - 'your-domain.com' # Replace with legitimate tenant domains
  condition: selection and not filter
falsepositives:
  - Legitimate application registration by admins
level: high

// Hunt for Linux curl-to-shell activity (ingested via Syslog/CEF or Linux Agent)
DeviceProcessEvents
| where Timestamp > ago(7d)
| where OSType == \"Linux\"
| where ProcessCommandLine has \"curl\" or ProcessCommandLine has \"wget\"
| where ProcessCommandLine has \"|\" 
| where ProcessCommandLine has_any(\"sh\", \"bash\", \"zsh\")
| project Timestamp, DeviceName, AccountName, ProcessCommandLine, InitiatingProcessFileName
| extend AlertDetails = \"Potential web-to-shell execution detected\"

// Hunt for suspicious OAuth Consents (Entra ID / Azure AD)
AuditLogs
| where Timestamp > ago(7d)
| where Category == \"ApplicationManagement\"
| where OperationName has \"Consent to application\"
| extend AppName = tostring(TargetResources[0].displayName)
| extend AppId = tostring(TargetResources[0].appId)
| where AppName !contains \"Microsoft\" // Add other verified publishers
| mvexpand AddedProperties = TargetResources[0].modifiedProperties
| where AddedProperties.displayName == \"ConsentContext.ActualConsent\"
| project Timestamp, User, AppName, AppId, AddedProperties.newValue

// Hunt for suspicious curl or wget commands piping to shell on Linux endpoints
SELECT Pid, Name, CommandLine, Exe, Username, Ctime
FROM pslist()
WHERE CommandLine =~ 'curl.*\\|.*sh'
   OR CommandLine =~ 'wget.*\\|.*sh'
   OR Name IN ('sh', 'bash', 'zsh')
   AND ParentCommandLine =~ 'cron'

// Scan for recent shell script modifications in /tmp or user directories
SELECT FullPath, Size, Mtime, Mode
FROM glob(globs='/tmp/*.sh', '/home/*/*.sh')
WHERE Mtime > now() - 7d

#!/bin/bash
# Remediation Script: Linux Flaw and Supply Chain Hardening
# Run with sudo privileges

echo \"[+] Checking for suspicious active shell processes...\"
# Identify processes matching curl | sh pattern
PIDS=$(ps aux | grep -E 'curl.*\|.*sh|wget.*\|.*sh' | grep -v grep | awk '{print $2}')
if [ -n \"$PIDS\" ]; then
    echo \"[!] Found suspicious processes. Killing...\"
    echo \"$PIDS\" | xargs kill -9
else
    echo \"[+] No suspicious web-to-shell processes found.\"
fi

echo \"[+] Auditing user crontabs for suspicious entries...\"
# Check for non-root crontabs executing shell scripts or network tools
for user in $(cut -d: -f1 /etc/passwd); do
    crontab -u $user -l 2>/dev/null | grep -E 'curl | sh|wget | sh|/bin/sh.*http' && echo \"[!] Suspicious cron found for user: $user\"
done

echo \"[+] Verifying Kernel Version...\"
# Placeholder for specific CVE check - Update kernel version check based on vendor advisory
CURRENT_KERNEL=$(uname -r)
echo \"Current Kernel: $CURRENT_KERNEL\"
# Logic to check against vulnerable versions would go here
# Example: if [[ \"$CURRENT_KERNEL\" < \"5.15.0\" ]]; then echo \"[!] Kernel is vulnerable\"; fi

echo \"[+] Updating package lists and available security patches...\"
apt-get update -qq

# Check for pending security updates
SEC_UPDATES=$(apt-get upgrade -s | grep -i security)
if [ -n \"$SEC_UPDATES\" ]; then
    echo \"[!] Security updates available. Please review and patch immediately:\"
    echo \"$SEC_UPDATES\"
else
    echo \"[+] No pending security updates found.\"
fi

echo \"[+] Script complete.\"