Cisco Secure Firewall - PHP2Shell Serialized Payload Activity


Description

This analytic detects suspicious PHP web application requests using Cisco Secure Firewall Threat Defense Intrusion Events. The matching network signature identifies a serialized input pattern associated with attempts to exploit PHP request handling. Investigate the source, targeted application, and related web server activity to determine whether the request was part of PHP2Shell exploitation.

Query · spl

`cisco_secure_firewall` EventType=IntrusionEvent SignatureID=67359
| fillnull
| stats min(_time) as firstTime
        max(_time) as lastTime
        values(SignatureID) as SignatureID
        values(signature) as signature
        values(class_desc) as class_desc
        values(MitreAttackGroups) as MitreAttackGroups
        values(InlineResult) as InlineResult
        values(InlineResultReason) as InlineResultReason
        values(src) as src
        values(dest_port) as dest_port
        values(rule) as rule
        values(transport) as transport
        values(app) as app
        by dest
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `cisco_secure_firewall___php2shell_serialized_payload_activity_filter`

Implementation guide

This search requires Cisco Secure Firewall Threat Defense logs with IntrusionEvent data. It uses the cisco_secure_firewall input macro, configure it for your environment (index, source, sourcetype). Ensure intrusion events are collected via the Splunk Add-on for Cisco Security Cloud (https://splunkbase.splunk.com/app/7404) and that the relevant intrusion policy is enabled.

Known false positives

  • Security testing or applications that legitimately submit serialized PHP data may trigger this signature. Review the request context and the targeted service.

Analyst notes

Known false positives: Security testing or applications that legitimately submit serialized PHP data may trigger this signature. Review the request context and the targeted service.

Raw source Cisco Secure Firewall - PHP2Shell Serialized Payload Activity · SPL
Esc
Published by splunk/security_content ↗, licensed under Apache 2.0 ↗. Reproduced here unmodified.
name: Cisco Secure Firewall - PHP2Shell Serialized Payload Activity
id: 60ad33a2-6fa8-4d13-b7be-fbe5167ea0ca
version: 1
creation_date: '2026-10-28'
modification_date: '2026-10-28'
author: Nasreddine Bencherchali, Splunk
status: production
type: TTP
description: |
    This analytic detects suspicious PHP web application requests using Cisco Secure Firewall Threat Defense Intrusion Events.
    The matching network signature identifies a serialized input pattern associated with attempts to exploit PHP request handling.
    Investigate the source, targeted application, and related web server activity to determine whether the request was part of PHP2Shell exploitation.
data_source:
    - Cisco Secure Firewall Threat Defense Intrusion Event
search: |
    `cisco_secure_firewall` EventType=IntrusionEvent SignatureID=67359
    | fillnull
    | stats min(_time) as firstTime
            max(_time) as lastTime
            values(SignatureID) as SignatureID
            values(signature) as signature
            values(class_desc) as class_desc
            values(MitreAttackGroups) as MitreAttackGroups
            values(InlineResult) as InlineResult
            values(InlineResultReason) as InlineResultReason
            values(src) as src
            values(dest_port) as dest_port
            values(rule) as rule
            values(transport) as transport
            values(app) as app
            by dest
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `cisco_secure_firewall___php2shell_serialized_payload_activity_filter`
how_to_implement: |
    This search requires Cisco Secure Firewall Threat Defense logs with IntrusionEvent data.
    It uses the `cisco_secure_firewall` input macro, configure it for your environment (index, source, sourcetype).
    Ensure intrusion events are collected via the Splunk Add-on for Cisco Security Cloud (https://splunkbase.splunk.com/app/7404) and that the relevant intrusion policy is enabled.
known_false_positives: |-
    Security testing or applications that legitimately submit serialized PHP data may trigger this signature. Review the request context and the targeted service.
references:
    - https://www.php2shell.com/
    - https://nvd.nist.gov/vuln/detail/CVE-2026-109618
    - https://nvd.nist.gov/vuln/detail/CVE-2026-109619
drilldown_searches:
    - name: View the detection results for - "$src$" and "$dest$"
      search: '%original_detection_search% | search src="$src$" dest="$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
finding:
    title: Suspicious PHP serialized input from [$src$] targeting [$dest$]
    entity:
        field: dest
        type: system
        score: 50
threat_objects:
    - field: signature
      type: signature
    - field: src
      type: ip_address
analytic_story:
    - Cisco Secure Firewall Threat Defense Analytics
    - PHP2Shell
asset_type: Network
cve:
    - CVE-2026-109618
    - CVE-2026-109619
mitre_attack_id:
    - T1190
product:
    - Splunk Enterprise
    - Splunk Cloud
    - Splunk Enterprise Security
category: network
security_domain: network
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/emerging_threats/php2shell/cisco_sfw_intrusion_events.log
          source: not_applicable
          sourcetype: cisco:sfw:estreamer
      test_type: unit

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