Terrance DeJesus
70411664cf
* normalizing hunting link generation * replacing header * adjusting quotes in f-strings * added source file to metadata * removed os dependency * address bug in source file links * reverting TOML loading * change all List type hinting to list * change all List type hinting to list * fixed accented characters in queries * reverted accent character removal; moved macos query and MD to macos folder
84 lines
3.4 KiB
Markdown
84 lines
3.4 KiB
Markdown
# Persistence via rc.local/rc.common
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---
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## Metadata
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- **Author:** Elastic
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- **Description:** This hunt identifies potential persistence mechanisms via rc.local and rc.common on Linux systems. RC scripts are used to start custom applications, services, scripts or commands during start-up. RC scripts have mostly been replaced by Systemd. However, through the "systemd-rc-local-generator", these files can be converted to services that run at boot. The query monitors for file creation or modification events in the /etc/rc.local and /etc/rc.common files, as well as processes started by these scripts. These activities can indicate attempts to establish persistence through rc.local modifications.
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- **UUID:** `a95f778f-2193-4a3d-bbbe-7b02d5740638`
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- **Integration:** [endpoint](https://docs.elastic.co/integrations/endpoint), [system](https://docs.elastic.co/integrations/system)
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- **Language:** `[ES|QL, SQL]`
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- **Source File:** [Persistence via rc.local/rc.common](../queries/persistence_via_rc_local.toml)
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## Query
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```sql
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from logs-endpoint.events.file-*
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| where @timestamp > now() - 30 day
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| where host.os.type == "linux" and event.type in ("creation", "change") and (file.path == "/etc/rc.local" or file.path == "/etc/rc.common")
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| eval persistence = case(file.path == "/etc/rc.local" or file.path == "/etc/rc.common", process.name, null)
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| stats pers_count = count(persistence), agent_count = count_distinct(agent.id) by process.executable
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| where pers_count > 0 and pers_count <= 3 and agent_count <= 3
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| sort pers_count asc
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| limit 100
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```
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```sql
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from logs-system.syslog-*
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| where @timestamp > now() - 30 day
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| where host.os.type == "linux" and process.name in ("rc.local", "rc.common")
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| stats cc = count(), host_count = count_distinct(host.name) by message
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| where host_count <= 3 and cc < 10
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| sort cc asc
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| limit 100
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```
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```sql
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SELECT * FROM systemd_units WHERE id = "rc-local.service"
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```
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```sql
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SELECT * FROM startup_items WHERE name = "rc-local.service"
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```
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```sql
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SELECT
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f.filename,
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f.path,
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u.username AS file_owner,
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g.groupname AS group_owner,
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datetime(f.atime, 'unixepoch') AS file_last_access_time,
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datetime(f.mtime, 'unixepoch') AS file_last_modified_time,
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datetime(f.ctime, 'unixepoch') AS file_last_status_change_time,
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datetime(f.btime, 'unixepoch') AS file_created_time,
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f.size AS size_bytes
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FROM
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file f
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LEFT JOIN
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users u ON f.uid = u.uid
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LEFT JOIN
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groups g ON f.gid = g.gid
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WHERE
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f.path in ('/etc/rc.local', '/etc/rc.common')
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```
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## Notes
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- This hunt includes multiple ES|QL and OSQuery queries to detect potential persistence mechanisms via rc.local on Linux systems.
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- Detects file creation or modification events in the /etc/rc.local and /etc/rc.common files, which are used for system initialization scripts.
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- Uses EVAL to tag potential persistence events and counts occurrences to identify unusual activity.
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- Monitors processes started by rc.local and rc.common scripts to detect potential persistence mechanisms.
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- Syslog hunting query is provided to complement the detection by analyzing syslog entries related to rc.local and rc.common processes.
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- OSQuery queries are provided to retrieve systemd unit states, startup items, and detailed file information related to rc.local and rc.common.
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## MITRE ATT&CK Techniques
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- [T1037.004](https://attack.mitre.org/techniques/T1037/004)
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- [T1546.003](https://attack.mitre.org/techniques/T1546/003)
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## License
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- `Elastic License v2`
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