Detect Disable or Modify System Firewall in IBM QRadar
Adversaries may disable or modify system firewalls in order to bypass controls limiting network usage. Changes could be disabling the entire mechanism as well as adding, deleting, or modifying particular rules. This can be done via command-line tools (netsh, iptables, ufw, pfctl), editing Windows Registry keys, or through the Windows Control Panel. On ESXi, firewall rules may be modified via esxcli. Adversaries may add new firewall rules for RDP on non-standard ports or open all traffic to enable C2, lateral movement, and data exfiltration.
MITRE ATT&CK
- Tactic
- Defense Evasion
- Technique
- T1562 Impair Defenses
- Sub-technique
- T1562.004 Disable or Modify System Firewall
- Canonical reference
- https://attack.mitre.org/techniques/T1562/004/
QRadar Detection Query
SELECT
DATEFORMAT(starttime, 'yyyy-MM-dd HH:mm:ss') AS EventTime,
sourceip AS SourceIP,
username AS UserName,
hostname AS HostName,
LOGSOURCENAME(logsourceid) AS LogSource,
CATEGORYNAME(category) AS Category,
"Process Name" AS ProcessName,
"Command" AS CommandLine,
CASE
WHEN "Command" ILIKE '%set allprofiles state off%' OR "Command" ILIKE '%opmode disable%' OR "Command" ILIKE '%-Enabled False%' OR "Command" ILIKE '%ufw disable%' OR "Command" ILIKE '%pfctl -d%' THEN 'Firewall Disabled'
WHEN "Command" ILIKE '%firewall add%' OR "Command" ILIKE '%New-NetFirewallRule%' THEN 'Firewall Rule Added'
WHEN "Command" ILIKE '%firewall delete%' OR "Command" ILIKE '%Remove-NetFirewallRule%' THEN 'Firewall Rule Deleted'
WHEN "Command" ILIKE '%iptables -F%' OR "Command" ILIKE '%iptables -X%' THEN 'IPTables Flushed'
WHEN "Command" ILIKE '%iptables -P%ACCEPT%' THEN 'IPTables Policy Set ACCEPT'
ELSE 'Other Firewall Modification'
END AS FirewallAction
FROM events
WHERE
LOGSOURCETYPEID IN (12, 13, 352)
AND starttime > NOW() - 1 DAYS
AND (
"Command" ILIKE '%netsh advfirewall set%'
OR "Command" ILIKE '%netsh advfirewall firewall add%'
OR "Command" ILIKE '%netsh advfirewall firewall delete%'
OR "Command" ILIKE '%netsh firewall set opmode disable%'
OR "Command" ILIKE '%Set-NetFirewallProfile%Enabled%False%'
OR "Command" ILIKE '%New-NetFirewallRule%'
OR "Command" ILIKE '%Remove-NetFirewallRule%'
OR "Command" ILIKE '%iptables -F%'
OR "Command" ILIKE '%iptables -X%'
OR "Command" ILIKE '%iptables -P INPUT ACCEPT%'
OR "Command" ILIKE '%ufw disable%'
OR "Command" ILIKE '%pfctl -d%'
OR "Command" ILIKE '%esxcli network firewall set%'
)
ORDER BY starttime DESC
LIMIT 1000Detects firewall disablement or modification events by querying QRadar process execution logs for command-line patterns associated with netsh, PowerShell firewall cmdlets, iptables, ufw, pfctl, and esxcli. Categorizes the action type for analyst triage.
Data Sources
Required Tables
False Positives & Tuning
- IT operations teams executing firewall reconfiguration scripts during planned maintenance windows documented in change management systems.
- Penetration testing or red team exercises conducted with written authorization against internal network segments.
- Cloud or container orchestration platforms dynamically adjusting host firewall rules during scaling or deployment operations.
Other platforms for T1562.004
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Disable Windows Firewall All Profiles
Expected signal: Sysmon Event ID 1: netsh.exe process creation. Windows Firewall Event ID 2003: Firewall profile changed. Each profile state change generates a separate event.
- Test 2Add Firewall Rule for RDP on Non-Standard Port
Expected signal: Sysmon Event ID 1: netsh.exe with 'firewall add rule'. Windows Firewall Event ID 2004: A rule has been added.
- Test 3Flush IPTables Rules on Linux
Expected signal: Auditd execve syscall records for iptables. Syslog entries for iptables commands. MDE DeviceProcessEvents if MDE for Linux is deployed.
References (4)
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