Non-Application Layer Protocol T1095

Events covered

8 catalog events are tagged with this technique by at least one rule.

Authoring guide

Patterns shared across the 42 rules above: which fields they filter on, what specific values they look for, and what they exclude. The catalog normalizes field names across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.

Fields filtered most (57 distinct)

The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.

Top indicator values (788 distinct)

Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique. Click a value to expand the rules under this technique that use it.

Exclusions (154 distinct)

Field/operator/value combinations excluded by rules under this technique (top-level not() clauses), sorted by how many rules exclude each. These are the false-positive paths the community has learned to filter out. A new rule that ignores the high-count entries here will likely fire on the same noisy paths. Click a value to expand the rules under this technique that exclude it.

Rules under this technique

Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.

Sigma 3 rules

• Netcat The Powershell Version
• PUA - Netcat Suspicious Execution
• Suspicious DNS Z Flag Bit Set

Elastic 18 rules

• File Transfer or Listener Established via Netcat
• IPSEC NAT Traversal Port Activity
• Netcat File Transfer or Listener Detected via Defend for Containers
• Netcat Listener Established via rlwrap
• Network Activity Detected via cat
• Network Connection Initiated by Suspicious SSHD Child Process
• Network Connection via Recently Compiled Executable
• Potential Command Shell via NetCat
• Potential Reverse Shell
• Potential Reverse Shell Activity via Terminal
• Potential Reverse Shell via Background Process
• Potential Reverse Shell via Child
• Potential Reverse Shell via Suspicious Binary
• Potential Reverse Shell via Suspicious Child Process
• Potential Reverse Shell via UDP
• Suspicious Interpreter Execution Detected via Defend for Containers
• Suspicious React Server Child Process
• Web Server Exploitation Detected via Defend for Containers

Splunk 10 rules

• Command and Control Detection (Windows Event Log)
• Detect Large ICMP Traffic
• Linux Proxy Socks Curl
• Meterpreter Reverse Shell (Windows Event Log)
• QEMU Network Tunneling - Windows (PowerShell)
• QEMU Network Tunneling - Windows (Sysmon)
• QEMU Network Tunneling - Windows (Windows Event Log)
• Tunneling Process Created (PowerShell)
• Tunneling Process Created (Sysmon)
• Tunneling Process Created (Windows Event Log)

Kusto 10 rules

• Anomaly found in Network Session Traffic (ASIM Network Session schema)
• CyberArkEPM - Uncommon process Internet access
• Detect port misuse by anomaly based detection (ASIM Network Session schema)
• Detect port misuse by static threshold (ASIM Network Session schema)
• Google DNS - IP check activity
• Google DNS - Multiple errors for source
• Google DNS - Multiple errors to same domain
• Google DNS - Request to dynamic DNS service
• Google DNS - UNC2452 (Nobelium) APT Group activity
• Ubiquiti - Possible connection to cryptominning pool

Panther 1 rule

• AWS Network ACL Restricts Insecure Protocols