Description
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, Boot or Logon Initialization Scripts, Unix Shell Configuration Modification, or tainting/hijacking other instrumental binary/configuration files via Hijack Execution Flow.
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)
Platforms
Sub-Techniques (2)
Mitigations (2)
Restrict File and Directory PermissionsM1022
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.(Citation: create_sym_links)
Privileged Account ManagementM1026
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.
Associated Software (1)
| ID | Name | Type | Context |
|---|---|---|---|
| S1242 | Qilin | Malware | [Qilin](https://attack.mitre.org/software/S1242) can use symbolic links to redirect file paths for remote and local objects and can use `chmod +x` to... |
References
- Falcon OverWatch Team. (2022, March 23). Falcon OverWatch Threat Hunting Contributes to Seamless Protection Against Novel BlackCat Attack. Retrieved May 5, 2022.
- Hybrid Analysis. (2018, June 12). c9b65b764985dfd7a11d3faf599c56b8.exe. Retrieved August 19, 2018.
- Hybrid Analysis. (2018, May 30). 2a8efbfadd798f6111340f7c1c956bee.dll. Retrieved August 19, 2018.
- Kaspersky Global Research & Analysis Team (GReAT). (2022). A Bad Luck BlackCat. Retrieved May 5, 2022.
- Microsoft. (2021, September 27). fsutil behavior. Retrieved January 14, 2022.
- Pereira, T. Huey, C. (2022, March 17). From BlackMatter to BlackCat: Analyzing two attacks from one affiliate. Retrieved May 5, 2022.
- Symantec Threat Hunter Team. (2021, December 16). Noberus: Technical Analysis Shows Sophistication of New Rust-based Ransomware. Retrieved January 14, 2022.
Frequently Asked Questions
What is T1222 (File and Directory Permissions Modification)?
T1222 is a MITRE ATT&CK technique named 'File and Directory Permissions Modification'. It belongs to the Defense Impairment tactic(s). 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...
How can T1222 be detected?
Detection of T1222 (File and Directory Permissions Modification) typically involves monitoring system logs, network traffic, and endpoint telemetry. Use SIEM rules, EDR solutions, and behavioral analytics to identify suspicious activity associated with this technique.
What mitigations exist for T1222?
There are 2 documented mitigations for T1222. Key mitigations include: Restrict File and Directory Permissions, Privileged Account Management.
Which threat groups use T1222?
While specific threat group attribution may vary, this technique has been observed in various real-world attacks. Check the MITRE ATT&CK website for the latest threat intelligence.