ATT&CK coverage › Technique
Credentials from Password Stores: Credentials from Web Browsers T1555.003
Adversaries may acquire credentials from web browsers by reading files specific to the target browser. Web browsers commonly save credentials such as website usernames and passwords so that they do not need to be entered manually in the future. Web browsers typically store the credentials in an encrypted format within a credential store; however, methods exist to extract plaintext credentials from web browsers.
Events covered
5 catalog events are tagged with this technique by at least one rule.
Authoring guide
Patterns shared across the 11 rules above: which fields they filter on, what specific values they look for, and what they exclude. Field names are normalized 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 (10 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 (77 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.
Common exclusions (5 distinct)
Field/operator/value combinations that rules under this technique routinely exclude (top-level not() clauses). 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.
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 6 rules
- Access to Browser Login Data
- HackTool - WinPwn Execution
- HackTool - WinPwn Execution - ScriptBlock
- Potential Browser Data Stealing
- PUA - WebBrowserPassView Execution
- SQLite Chromium Profile Data DB Access
Splunk 4 rules
- Non Chrome Process Accessing Chrome Default Dir
- Non Firefox Process Access Firefox Profile Dir
- Windows Credentials from Password Stores Chrome Copied in TEMP Dir
- Windows Credentials from Web Browsers Saved in TEMP Folder