Forced Authentication T1187

Events covered

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

Authoring guide

Patterns shared across the 21 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 (33 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 (87 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 (4 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 7 rules

• Attempts of Kerberos Coercion Via DNS SPN Spoofing
• NTLM Hash Leak Via Curl NTLM Authentication
• PetitPotam Suspicious Kerberos TGT Request
• Possible PetitPotam Coerce Authentication Attempt
• Potential CVE-2026-33829 Exploitation - Windows Snipping Tool Remote File Path URI
• Suspicious Creation of .library-ms File — Potential CVE-2025-24054 Exploit
• Suspicious DNS Query Indicating Kerberos Coercion via DNS Object SPN Spoofing

Elastic 7 rules

• Potential Computer Account NTLM Relay Activity
• Potential Kerberos Coercion via DNS-Based SPN Spoofing
• Potential Kerberos Relay Attack against a Computer Account
• Potential Kerberos SPN Spoofing via Suspicious DNS Query
• Potential Local NTLM Relay via HTTP
• Potential Machine Account Relay Attack via SMB
• Potential NTLM Relay Attack against a Computer Account

Splunk 6 rules

• DNS Kerberos Coercion
• PetitPotam Network Share Access Request
• Windows Credential Target Information Structure in Commandline
• Windows Kerberos Coercion via DNS
• Windows Short Lived DNS Record
• Windows Theme File Creation in Unusual Location

Kusto 1 rule

• NTLM Relay Attack