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Suspicious Calendar File Modification
editSuspicious Calendar File Modification
editIdentifies suspicious modifications of the calendar file by an unusual process. Adversaries may create a custom calendar notification procedure to execute a malicious program at a recurring interval to establish persistence.
Rule type: query
Rule indices:
- logs-endpoint.events.*
- auditbeat-*
Severity: medium
Risk score: 47
Runs every: 5 minutes
Searches indices from: now-9m (Date Math format, see also Additional look-back time
)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Host
- macOS
- Threat Detection
- Persistence
Version: 100 (version history)
Added (Elastic Stack release): 7.12.0
Last modified (Elastic Stack release): 8.5.0
Rule authors: Elastic
Rule license: Elastic License v2
Potential false positives
editTrusted applications for managing calendars and reminders.
Rule query
editevent.category:file and event.action:modification and file.path:/Users/*/Library/Calendars/*.calendar/Events/*.ics and process.executable: (* and not ( /System/Library/* or /System/Applications/Calendar.app/Contents/MacOS/* or /System/Applications/Mail.app/Contents/MacOS/Mail or /usr/libexec/xpcproxy or /sbin/launchd or /Applications/* ) )
Threat mapping
editFramework: MITRE ATT&CKTM
-
Tactic:
- Name: Persistence
- ID: TA0003
- Reference URL: https://attack.mitre.org/tactics/TA0003/
-
Technique:
- Name: Event Triggered Execution
- ID: T1546
- Reference URL: https://attack.mitre.org/techniques/T1546/
Rule version history
edit- Version 100 (8.5.0 release)
-
- Formatting only
- Version 3 (8.4.0 release)
-
-
Updated query, changed from:
event.category:file and event.action:modification and file.path:/Users/*/Library/Calendars/*.calendar/Events/*.ics and process.executable: (* and not ( /System/Library/* or /System/Applications/Calendar.app/Contents/MacOS/* or /usr/libexec/xpcproxy or /sbin/launchd or /Applications/* ) )
-