File and Directory Permissions Modification T1222
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.).
Events covered
8 catalog events are tagged with this technique by at least one rule.
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Security-Auditing | Event ID 4662 | An operation was performed on an object. |
| Security-Auditing | Event ID 4688 | A new process has been created. |
| Security-Auditing | Event ID 5124 | A security setting was updated on OCSP Responder Service. |
| Security-Auditing | Event ID 5136 | A directory service object was modified. |
| Security-Auditing | Event ID 5143 | A network share object was modified. |
| PowerShell | Event ID 4103 | Payload Context: ContextInfo User Data: UserData. |
| PowerShell | Event ID 4104 | Creating Scriptblock text (MessageNumber of MessageTotal). |
Authoring guide
Patterns shared across the 50 rules above: which fields they filter on, what specific values they look for, and what they exclude. The catalog normalizes field names across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.
Fields filtered most (32 distinct)
The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.
Top indicator values (196 distinct)
Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique. Click a value to expand the rules under this technique that use it.
Exclusions (27 distinct)
Field/operator/value combinations excluded by rules under this technique (top-level not() clauses), sorted by how many rules exclude each. These are the false-positive paths the community has learned to filter out. A new rule that ignores the high-count entries here will likely fire on the same noisy paths. Click a value to expand the rules under this technique that exclude it.
Rules under this technique
Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.
Sigma 12 rules
- AD Object WriteDAC Access
- Computer account modifying Active Directory permissions
- Computer account modifying Active Directory permissions (PrivExchange)
- File or Folder Permissions Modifications
- OCSP responder security settings changed
- Potentially Suspicious NTFS Symlink Behavior Modification
- PowerShell Script Change Permission Via Set-Acl - PsScript
- PowerShell Set-Acl On Windows Folder - PsScript
- Replication privileges granted to perform DCSync attack
- Suspicious permissions modification on a network share
- Suspicious Recursive Takeown
- WannaCry Ransomware Activity
Elastic 4 rules
- Adding Hidden File Attribute via Attrib
- File and Directory Permissions Modification
- System File Ownership Change
- WRITEDAC Access on Active Directory Object
Splunk 34 rules
- Excessive Usage Of Cacls App
- File_Folder Hidden - Windows (PowerShell)
- File_Folder Hidden - Windows (Sysmon)
- File_Folder Hidden - Windows (Windows Event Log)
- Full Control Permissions Granted to Everyone - Windows (Sysmon)
- Full Control Permissions Granted to Everyone - Windows (Windows Event Log)
- Hiding Files And Directories With Attrib exe
- Icacls Deny Command
- ICACLS Grant Command
- Modify ACL permission To Files Or Folder
- Permission Modification using Takeown App
- Permissions Replaced by icacls - Windows (PowerShell)
- Permissions Replaced by icacls - Windows (Sysmon)
- Permissions Replaced by icacls - Windows (Windows Event Log)
- Read-Only Attribute Removed - Windows (PowerShell)
- Read-Only Attribute Removed - Windows (Sysmon)
- Read-Only Attribute Removed - Windows (Windows Event Log)
- Windows AD Dangerous Deny ACL Modification
- Windows AD Dangerous Group ACL Modification
- Windows AD Dangerous User ACL Modification
- Windows AD DCShadow Privileges ACL Addition
- Windows AD Domain Root ACL Deletion
- Windows AD Domain Root ACL Modification
- Windows AD GPO New CSE Addition
- Windows AD Hidden OU Creation
- Windows AD Object Owner Updated
- Windows AD Suspicious Attribute Modification
- Windows File and Directory Enable ReadOnly Permissions
- Windows File and Directory Permissions Enable Inheritance
- Windows File and Directory Permissions Remove Inheritance
- Windows Files and Dirs Access Rights Modification Via Icacls
- Windows SubInAcl Execution
- Windows SymbolicLink-Testing-Tools Utility Execution
- Windows Symlink Evaluation Change via Fsutil