Detectionmediumtest

Persistence Via Cron Files

Detects creation of cron file or files in Cron directories which could indicates potential persistence.

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Launch
Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research), MSTICCreated Fri Oct 15Updated Sat Dec 316c4e2f43-d94d-4ead-b64d-97e53fa2bd05linux
Log Source
LinuxFile Event
ProductLinux← raw: linux
CategoryFile Event← raw: file_event

Events for file system activity including creation, modification, and deletion.

Detection Logic
Detection Logic2 selectors
detection:
    selection1:
        TargetFilename|startswith:
            - '/etc/cron.d/'
            - '/etc/cron.daily/'
            - '/etc/cron.hourly/'
            - '/etc/cron.monthly/'
            - '/etc/cron.weekly/'
            - '/var/spool/cron/crontabs/'
    selection2:
        TargetFilename|contains:
            - '/etc/cron.allow'
            - '/etc/cron.deny'
            - '/etc/crontab'
    condition: 1 of selection*
False Positives

Any legitimate cron file.

Rule Metadata
Rule ID
6c4e2f43-d94d-4ead-b64d-97e53fa2bd05
Status
test
Level
medium
Type
Detection
Created
Fri Oct 15
Modified
Sat Dec 31
Path
rules/linux/file_event/file_event_lnx_persistence_cron_files.yml
Raw Tags
attack.privilege-escalationattack.executionattack.persistenceattack.t1053.003
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