T1222
File and Directory Permissions Modification
ESXi · Linux · macOS · Windowsnothing on this site yetT1222 on attack.mitre.org
Adversaries may modify file or directory permissions/attributes to evade access control lists (ACLs) and access protected files. 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.).
If this is happening now
Checklists and playbooks to open while the alert is still live.
Playbook for this stage
Ransomware, suspected or confirmed
Files renamed or unreadable, a ransom note, or backup deletion commands seen.
how MITRE says to see it
Multi-Platform File and Directory Permissions Modification Detection Strategy
- Sequential behavioral chain of privilege escalation through permission modification: (1) Process creation of permission-modifying utilities (icacls, takeown, attrib, cacls), (2) Correlation with unusual user context or timing, (3) DACL modification events targeting sensitive files/directories, (4) Subsequent file...
- Behavioral sequence of unauthorized privilege escalation via permission modification: (1) chmod/chown/setfacl process execution with suspicious parameters, (2) Targeting of critical system files or unusual permission values, (3) Correlation with non-privileged user context or unusual timing patterns, (4) Follow-on...
- macOS-specific permission modification behavioral chain: (1) chmod/chown/chflags process execution, (2) System Integrity Protection (SIP) bypass attempts, (3) Extended attribute (xattr) modifications, (4) Unified log correlation with file system events, (5) Subsequent access to previously restricted resources
- ESXi hypervisor permission modification behavioral chain: (1) SSH access to ESXi host, (2) chmod/chown execution on VMFS datastore files or system configuration, (3) Modification of VM configuration files (.vmx) or virtual disk permissions, (4) Hostd service log correlation, (5) vCenter permission change events if...
what reduces it
- M1022 Restrict File and Directory Permissions. Applying more restrictive permissions to files and directories could prevent adversaries from modifying their access control lists. Additionally, ensure that user settings regarding local and remote symbolic links are properly set or disabled where unneeded.
- M1026 Privileged Account Management. Ensure critical system files as well as those known to be abused by adversaries have restrictive permissions and are owned by an appropriately privileged account, especially if access is not required by users nor will inhibit system functionality.