---
title: Potential Citrix NetScaler CVE-2026-3055 Exploitation Attempt
id: 8f4a2b19-0d7e-4c3a-9f1b-2c3d4e5f6a78
status: experimental
description: Detects potential exploit attempts against Citrix NetScaler appliances leveraging CVE-2026-3055 based on known URI patterns or request anomalies.
references:
  - https://www.infosecurity-magazine.com/news/critical-citrix-netscaler/
author: Security Arsenal
date: 2026/05/15
tags:
  - attack.initial_access
  - attack.t1190
logsource:
  category: network_connection
  product: linux
detection:
  selection:
    DestinationPort: 443
    Initiated: 'false'
  condition: selection
falsepositives:
  - Legitimate management traffic from known admin IPs
level: high
---
title: Suspicious Outbound Connection from NetScaler Appliance
id: a1b2c3d4-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects suspicious outbound network connections from a NetScaler appliance, potentially indicating C2 beaconing or data exfiltration post-exploitation.
references:
  - https://attack.mitre.org/techniques/T1071/
author: Security Arsenal
date: 2026/05/15
tags:
  - attack.command_and_control
  - attack.t1071.004
logsource:
  category: network_connection
  product: linux
detection:
  selection:
    SourcePort|in:
      - 443
      - 80
    DestinationPort|notin:
      - 53
      - 443
      - 80
      - 22
    Initiated: 'true'
  condition: selection
falsepositives:
  - Legitimate API calls or health checks to non-standard ports
level: medium

// Hunt for suspicious management interface access to Citrix NetScaler
// This looks for spikes in 401 or 403 errors which may indicate scanning
CommonSecurityLog
| where DeviceVendor contains "Citrix"
| where DeviceProduct in ("NetScaler", "ADC")
| where DestinationPort == 443
| where Activity == "Denied" or Activity == "403" or Activity == "401"
| summarize count() by SourceIP, bin(TimeGenerated, 5m)
| where count_ > 10
| order by count_ desc


// Detect potential successful exploitation followed by command execution
// Look for web requests returning 200 OK status with suspicious URI lengths
CommonSecurityLog
| where DeviceVendor contains "Citrix"
| where DeviceProduct in ("NetScaler", "ADC")
| where DestinationPort == 443
| where RequestURL has "/nitro/v1/config/"
| extend URLLength = strlen(RequestURL)
| where URLLength > 200 // Abnormally long requests often indicate payloads
| project TimeGenerated, SourceIP, DestinationIP, RequestURL, URLLength

-- Hunt for unusual processes spawned by accounts often used in lateral movement
SELECT Pid, Name, CommandLine, Exe, Username, CreateTime
FROM pslist()
WHERE Name IN ('cmd.exe', 'powershell.exe', 'wmiexec.exe')
  AND Username =~ '.*\\ADMIN$' OR Username =~ '.*\\Administrator'
  AND CreateTime > timestamp(now) - timedelta(hours=24)


-- Hunt for new scheduled tasks created in the last 24 hours
-- Attackers often use scheduled tasks for persistence on Windows endpoints
SELECT Name, Action, Trigger, Author, Date
FROM glob(globs='C:\\Windows\\System32\\Tasks\\*')
WHERE Mtime > timestamp(now) - timedelta(hours=24)

<#
.SYNOPSIS
    Checks Citrix NetScaler version against patched builds for CVE-2026-3055.
.DESCRIPTION
    Connects to the NetScaler NITRO API to retrieve the installed version.
#>

$NsIp = "YOUR_NETSCALER_IP"
$Credentials = Get-Credential

try {
    $Url = "https://$NsIp/nitro/v1/config/nsversion"
    $Response = Invoke-RestMethod -Uri $Url -Method Get -Credential $Credentials -SkipCertificateCheck
    
    Write-Host "NetScaler Version: $($Response.nsversion.version)"
    
    # Compare against known safe build logic here
    if ($Response.nsversion.version -lt "14.1-30.50") {
        Write-Host "WARNING: Version is vulnerable to CVE-2026-3055." -ForegroundColor Red
    } else {
        Write-Host "Version appears patched." -ForegroundColor Green
    }
}
 catch {
    Write-Error "Failed to connect: $_"
}