Browse Rules

Abnormally Large DNS Response

Specially crafted DNS requests can manipulate a known overflow vulnerability in some Windows DNS servers, resulting in Remote Code Execution (RCE) or a Denial of Service (DoS) from crashing the service.

Web Server Potential SQL Injection Request

This rule detects potential SQL injection attempts in web server requests by identifying common SQL injection patterns in URLs. Such activity may indicate reconnaissance or exploitation attempts by attackers trying to manipulate backend databases or extract sensitive information.

Web Server Cloud Metadata SSRF Request

Detects HTTP requests to web servers whose URL or query string references cloud instance metadata endpoints or equivalent encoded variants. Attackers exploit server-side request forgery (SSRF) vulnerabilities in web applications to reach link-local metadata services on AWS, GCP, Azure, and similar cloud providers and harvest temporary credentials, tokens, or instance details.

RPC (Remote Procedure Call) from the Internet

This rule detects network events that may indicate the use of RPC traffic from the Internet. RPC is commonly used by system administrators to remotely control a system for maintenance or to use shared resources. It should almost never be directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or backdoor vector.

RPC (Remote Procedure Call) to the Internet

This rule detects network events that may indicate the use of RPC traffic to the Internet. RPC is commonly used by system administrators to remotely control a system for maintenance or to use shared resources. It should almost never be directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or backdoor vector.

Splunk Enterprise PostgreSQL Recovery Endpoint Injection Artifacts

Detects CVE-2026-20253 exploit artifacts against the Splunk Enterprise PostgreSQL sidecar recovery endpoints via complementary signals. Where endpoint or Network Packet Capture request-body logging is available, the rule matches PostgreSQL connection-string injection keywords, suspicious `backupFile` destinations, and known filesystem artifacts used to pivot from backup/restore primitives to file write or RCE. It also detects vulnerable recovery endpoint probing and empty-password Basic auth cre

Potential DNS Tunneling via Long and Unique Subdomains

Identifies a client generating many unique, unusually long DNS query names to the same registered domain within a five-minute window. Malware DNS tunnels and DNS command-and-control commonly encode data in lengthy subdomain portions under one apex domain.

SMB (Windows File Sharing) Activity from the Internet

This rule detects network events that may indicate inbound Windows file sharing (SMB or CIFS) traffic originating from the Internet. SMB should never be directly reachable from the Internet, as it is a primary target for exploitation by threat actors seeking initial access. Inbound SMB from a public IP is a direct precondition for attacks such as EternalBlue (MS17-010) and related SMB remote code execution vulnerabilities.

SMB (Windows File Sharing) Activity to the Internet

This rule detects network events that may indicate the use of Windows file sharing (also called SMB or CIFS) traffic to the Internet. SMB is commonly used within networks to share files, printers, and other system resources amongst trusted systems. It should almost never be directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or backdoor vector or for data exfiltration.

RDP (Remote Desktop Protocol) from the Internet

This rule detects network events that may indicate the use of RDP traffic from the Internet. RDP is commonly used by system administrators to remotely control a system for maintenance or to use shared resources. It should almost never be directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or backdoor vector.

SMTP to the Internet on Port 26/TCP

This rule detects events that may indicate use of SMTP on TCP port 26 from an internal host to an external destination. This port is commonly used by several popular mail transfer agents to deconflict with the default SMTP port 25. This port has also been used by a malware family called BadPatch for command and control of Windows systems. The rule is scoped to outbound traffic (internal source to external destination) to focus on the command and control and exfiltration use cases, rather than be

Newly Observed IPSEC NAT Traversal Peer

This rule identifies outbound IPSEC NAT Traversal (NAT-T) traffic to an external destination IP that was not observed during the previous 5 days. IPSEC is a VPN technology that allows one system to talk to another using encrypted tunnels. NAT Traversal encapsulates IPSEC ESP traffic in UDP and, once a NAT device is detected, both peers float to UDP port 4500 for the tunnel data channel. Newly observed external NAT-T peers may indicate unauthorized VPN use or an adversary tunneling command and co

Splunk Enterprise PostgreSQL Backup-to-Restore Potential RCE Sequence

Detects a POST to the Splunk Enterprise PostgreSQL backup endpoint followed by a POST to the restore endpoint from the same client to the same host within a 15-minute window. This sequence is unusual and can align with the public CVE-2026-20253 pre-authentication RCE chain, where an attacker stages a database dump via the backup path and executes attacker-controlled SQL via the restore path.

Potential cPanel WHM CRLF Authentication Bypass (CVE-2026-41940)

Identifies the network signature of CVE-2026-41940, a pre-auth root-level authentication bypass in cPanel and WebHost Manager (WHM) caused by a CRLF injection in the session writer. The exploit-inherent shape on the wire is a "GET /" request to a cPanel/WHM admin port (typically TCP/2087, 2086, 2083, 2082, 2095, 2096) carrying an "Authorization: Basic" header whose base64-decoded value contains CRLF-injected session fields, which causes cpsrvd to respond with a 3xx redirect whose "Location" head

Potential DNS Rebinding from Public to Private Address

Identifies a client resolving the same public registered domain to both a public IP address and a private, loopback, link-local, unique-local IPv6, or shared address. This includes both address classes being observed at the same timestamp, and a public answer followed within five minutes by a private answer where the minimum TTL across all answer records in the private-answer events is 60 seconds or less. Either pattern is consistent with DNS rebinding that pivots browser or application trust to