Detectionlowtest

Local System Accounts Discovery - Linux

Detects enumeration of local system accounts. This information can help adversaries determine which local accounts exist on a system to aid in follow-on behavior.

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Launch

Alejandro Ortuno, oscd.community, CheraghiMiladCreated Thu Oct 08Updated Tue Dec 10b45e3d6f-42c6-47d8-a478-df6bd6cf534clinux

Log Source

LinuxProcess Creation

ProductLinux← raw: linux

CategoryProcess Creation← raw: process_creation

Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.

Detection Logic

detection:
    selection_1:
        Image|endswith: '/lastlog'
    selection_2:
        CommandLine|contains: '''x:0:'''
    selection_3:
        Image|endswith:
            - '/cat'
            - '/ed'
            - '/head'
            - '/more'
            - '/nano'
            - '/tail'
            - '/vi'
            - '/vim'
            - '/less'
            - '/emacs'
            - '/sqlite3'
            - '/makemap'
        CommandLine|contains:
            - '/etc/passwd'
            - '/etc/shadow'
            - '/etc/sudoers'
            - '/etc/spwd.db'
            - '/etc/pwd.db'
            - '/etc/master.passwd'
    selection_4:
        Image|endswith: '/id'
    selection_5:
        Image|endswith: '/lsof'
        CommandLine|contains: '-u'
    condition: 1 of selection*