Potential Suspicious File Edit

edit

This rule monitors for the potential edit of a suspicious file. In Linux, when editing a file through an editor, a temporary .swp file is created. By monitoring for the creation of this .swp file, we can detect potential file edits of suspicious files. The execution of this rule is not a clear sign of the file being edited, as just opening the file through an editor will trigger this event. Attackers may alter any of the files added in this rule to establish persistence, escalate privileges or perform reconnaisance on the system.

Rule type: eql

Rule indices:

  • logs-endpoint.events.*
  • endgame-*

Severity: low

Risk score: 21

Runs every: 60m

Searches indices from: now-119m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 1

References: None

Tags:

  • Domain: Endpoint
  • OS: Linux
  • Use Case: Threat Detection
  • Tactic: Persistence
  • Tactic: Privilege Escalation
  • Data Source: Elastic Endgame
  • Rule Type: BBR
  • Data Source: Elastic Defend

Version: 3

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule query

edit
file where event.action in ("creation", "file_create_event") and file.extension == "swp" and
file.path : (
  /* common interesting files and locations */
  "/etc/.shadow.swp", "/etc/.shadow-.swp", "/etc/.shadow~.swp", "/etc/.gshadow.swp", "/etc/.gshadow-.swp",
  "/etc/.passwd.swp", "/etc/.pwd.db.swp", "/etc/.master.passwd.swp", "/etc/.spwd.db.swp", "/etc/security/.opasswd.swp",
  "/etc/.environment.swp", "/etc/.profile.swp", "/etc/sudoers.d/.*.swp", "/etc/ld.so.conf.d/.*.swp",
  "/etc/init.d/.*.swp", "/etc/.rc.local.swp", "/etc/rc*.d/.*.swp", "/dev/shm/.*.swp", "/etc/update-motd.d/.*.swp",
  "/usr/lib/update-notifier/.*.swp",

  /* service, timer, want, socket and lock files */
  "/etc/systemd/system/.*.swp", "/usr/local/lib/systemd/system/.*.swp", "/lib/systemd/system/.*.swp",
  "/usr/lib/systemd/system/.*.swp","/home/*/.config/systemd/user/.*.swp", "/run/.*.swp", "/var/run/.*.swp/",

  /* profile and shell configuration files */
  "/home/*.profile.swp", "/home/*.bash_profile.swp", "/home/*.bash_login.swp", "/home/*.bashrc.swp", "/home/*.bash_logout.swp",
  "/home/*.zshrc.swp", "/home/*.zlogin.swp", "/home/*.tcshrc.swp", "/home/*.kshrc.swp", "/home/*.config.fish.swp",
  "/root/*.profile.swp", "/root/*.bash_profile.swp", "/root/*.bash_login.swp", "/root/*.bashrc.swp", "/root/*.bash_logout.swp",
  "/root/*.zshrc.swp", "/root/*.zlogin.swp", "/root/*.tcshrc.swp", "/root/*.kshrc.swp", "/root/*.config.fish.swp"
)

Framework: MITRE ATT&CKTM