Event 4817: Auditing settings on an object were changed.

Adversaries may modify file or directory permissions/attributes to evade access control lists (ACLs) and access protected files.(Citation: Hybrid Analysis Icacls1 June 2018)(Citation: Hybrid Analysis Icacls2 May 2018) File and directory permissions are commonly managed by ACLs configured by the file or directory owner, or users with the appropriate permissions. File and directory ACL implementations vary by platform, but generally explicitly designate which users or groups can perform which actions (read, write, execute, etc.). Modifications may include changing specific access rights, which may require taking ownership of a file or directory and/or elevated permissions depending on the file or directory’s existing permissions. This may enable malicious activity such as modifying, replacing, or deleting specific files or directories. Specific file and directory modifications may be a required step for many techniques, such as establishing Persistence via [Accessibility Features](https://attack.mitre.org/techniques/T1546/008), [Boot or Logon Initialization Scripts](https://attack.mitre.org/techniques/T1037), [Unix Shell Configuration Modification](https://attack.mitre.org/techniques/T1546/004), or tainting/hijacking other instrumental binary/configuration files via [Hijack Execution Flow](https://attack.mitre.org/techniques/T1574). Adversaries may also change permissions of symbolic links. For example, malware (particularly ransomware) may modify symbolic links and associated settings to enable access to files from local shortcuts with remote paths.(Citation: new_rust_based_ransomware)(Citation: bad_luck_blackcat)(Citation: falconoverwatch_blackcat_attack)(Citation: blackmatter_blackcat)(Citation: fsutil_behavior)

Adversaries may maliciously modify components of a victim environment in order to hinder or disable defensive mechanisms. This not only involves impairing preventative defenses, such as firewalls and anti-virus, but also detection capabilities that defenders can use to audit activity and identify malicious behavior. This may also span both native defenses as well as supplemental capabilities installed by users and administrators. Adversaries may also impair routine operations that contribute to defensive hygiene, such as blocking users from logging out, preventing a system from shutting down, or disabling or modifying the update process. Adversaries could also target event aggregation and analysis mechanisms, or otherwise disrupt these procedures by altering other system components. These restrictions can further enable malicious operations as well as the continued propagation of incidents.(Citation: Google Cloud Mandiant UNC3886 2024)(Citation: Emotet shutdown)