Network Share Discovery T1135
Adversaries may look for folders and drives shared on remote systems as a means of identifying sources of information to gather as a precursor for Collection and to identify potential systems of interest for Lateral Movement. Networks often contain shared network drives and folders that enable users to access file directories on various systems across a network.
Events covered
9 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 4672 | Special privileges assigned to new logon. |
| Security-Auditing | Event ID 4688 | A new process has been created. |
| Security-Auditing | Event ID 4769 | A Kerberos service ticket was requested. |
| Security-Auditing | Event ID 5140 | A network share object was accessed. |
| Security-Auditing | Event ID 5143 | A network share object was modified. |
| Security-Auditing | Event ID 5145 | A network share object was checked to see whether client can be granted desired access. |
| 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 28 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 (27 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 (203 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 (32 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 9 rules
- File Explorer Folder Opened Using Explorer Folder Shortcut Via Shell
- HackTool - SharpView Execution
- Net.EXE Execution
- Network share discovery and/or connection via commandline
- Potential Dridex Activity
- PUA - Advanced IP Scanner Execution
- PUA - Advanced Port Scanner Execution
- SharpHound enumeration via SMB named pipes
- Turla Group Lateral Movement
Elastic 3 rules
- Potential Network Share Discovery
- System Service Discovery through built-in Windows Utilities
- Windows Network Enumeration
Splunk 14 rules
- Advanced IP or Port Scanner Execution
- IcedID Discovery Commands (EDR)
- IcedID Discovery Commands (Sysmon)
- IcedID Discovery Commands (Windows Event Log)
- Network Share Discovery Via Dir Command
- PowerHuntShares Commands (PowerShell)
- PowerHuntShares Commands (Sysmon)
- PowerHuntShares Commands (Windows Event Log)
- PowerView_SharpView Commands (PowerShell)
- Windows Administrative Shares Accessed On Multiple Hosts
- Windows File Share Discovery With Powerview
- Windows Large Number of Computer Service Tickets Requested
- Windows Network Share Interaction Via Net
- Windows Special Privileged Logon On Multiple Hosts