Steal Web Session Cookie T1539

Events covered

5 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 (54 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 (125 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 (27 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 2 rules

• SQLite Chromium Profile Data DB Access
• SQLite Firefox Profile Data DB Access

Elastic 12 rules

• Browser Process Spawned from an Unusual Parent
• Entra ID Microsoft Authentication Broker Sign-In with Non-Standard User Agent
• Entra ID Potential AiTM Sign-In via OfficeHome (Tycoon2FA)
• First Time Python Accessed Sensitive Credential Files
• M365 Potential AiTM UserLoggedIn via Office App (Tycoon2FA)
• Manual Loading of a Suspicious Chromium Extension
• Multiple Device Token Hashes for Single Okta Session
• Okta AiTM Session Cookie Replay
• Okta Multiple OS Names Detected for a Single DT Hash
• Potential Cookies Theft via Browser Debugging
• Suspicious Web Browser Sensitive File Access
• WebProxy Settings Modification

Splunk 1 rule

• Okta Suspicious Use of a Session Cookie

Kusto 1 rule

• Detect device token stealing with WDAC

YARA-L 1 rule

• Okta Suspicious Use Of A Session Cookie

Panther 4 rules

• AppOmni Alert Passthrough
• Okta Login Without Push
• Okta Potentially Stolen Session
• Potential Compromised Okta Credentials