Boot or Logon Initialization Scripts: RC Scripts T1037.004
Tactics: Persistence, Privilege Escalation
Adversaries may establish persistence by modifying RC scripts, which are executed during a Unix-like system’s startup. These files allow system administrators to map and start custom services at startup for different run levels. RC scripts require root privileges to modify.
Events covered
4 catalog events are tagged with this technique by at least one rule.
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 11 | FileCreate |
| ESF | open | File Open (NOTIFY) |
| ESF | create | File or Directory Create (NOTIFY) |
| ESF | write | File Write (NOTIFY) |
Authoring guide
Patterns shared across the 11 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 (16 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 (395 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 (177 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.
Elastic 10 rules
- Executable Bit Set for Potential Persistence Script
- GenAI Process Accessing Sensitive Files
- Pod or Container Creation with Suspicious Command-Line
- Potential Execution of rc.local Script
- Potential Persistence via File Modification
- Potential Suspicious File Edit
- rc.local/rc.common File Creation
- Suspicious Network Activity to the Internet by Previously Unknown Executable
- Suspicious rc.local Error Message
- System V Init Script Created