ATT&CK coverage › Technique
System Owner/User Discovery T1033
Adversaries may attempt to identify the primary user, currently logged in user, set of users that commonly uses a system, or whether a user is actively using the system. They may do this, for example, by retrieving account usernames or by using OS Credential Dumping. The information may be collected in a number of different ways using other Discovery techniques, because user and username details are prevalent throughout a system and include running process ownership, file/directory ownership, session information, and system logs. Adversaries may use the information from System Owner/User Discovery during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.
Events covered
3 catalog events are tagged with this technique by at least one rule.
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 1 | Process creation |
| Security-Auditing | 4688 | A new process has been created. |
| PowerShell | 4104 | Creating Scriptblock text (MessageNumber of MessageTotal). |
Authoring guide
Patterns shared across the 22 rules above: which fields they filter on, what specific values they look for, and what they exclude. Field names are normalized 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 (8 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 (266 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.
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 20 rules
- Chopper Webshell Process Pattern
- Computer Discovery And Export Via Get-ADComputer Cmdlet
- Computer Discovery And Export Via Get-ADComputer Cmdlet - PowerShell
- Enumerate All Information With Whoami.EXE
- Get-ADUser Enumeration Using UserAccountControl Flags
- Group Membership Reconnaissance Via Whoami.EXE
- HackTool - SharpLdapWhoami Execution
- HackTool - SharpView Execution
- Local Accounts Discovery
- Renamed Whoami Execution
- Security Privileges Enumeration Via Whoami.EXE
- Suspicious PowerShell Get Current User
- User Discovery And Export Via Get-ADUser Cmdlet
- User Discovery And Export Via Get-ADUser Cmdlet - PowerShell
- Webshell Detection With Command Line Keywords
- Webshell Hacking Activity Patterns
- WhoAmI as Parameter
- Whoami.EXE Execution Anomaly
- Whoami.EXE Execution From Privileged Process
- Whoami.EXE Execution With Output Option