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.

File sharing over a Windows network occurs over the SMB protocol. ^[1] ^[2] Net can be used to query a remote system for available shared drives using the net view \remotesystem command. It can also be used to query shared drives on the local system using net share.

Cloud virtual networks may contain remote network shares or file storage services accessible to an adversary after they have obtained access to a system. For example, AWS, GCP, and Azure support creation of Network File System (NFS) shares and Server Message Block (SMB) shares that may be mapped on endpoint or cloud-based systems.^[3]^[4]

ID: T1135

Sub-techniques: No sub-techniques

Tactic: Discovery

Platforms: AWS, Azure, GCP, Linux, Windows, macOS

Permissions Required: User

Data Sources: Network protocol analysis, Process command-line parameters, Process monitoring, Process use of network

CAPEC ID: CAPEC-643

Contributors: Praetorian

Version: 2.1

Created: 14 December 2017

Last Modified: 15 March 2020

Version Permalink

Live Version

Procedure Examples

Name	Description
APT1	APT1 listed connected network shares.^[23]
APT32	APT32 used the `net view` command to show all shares available, including the administrative shares such as `C$` and `ADMIN$`.^[28]
APT39	APT39 has used the post exploitation tool CrackMapExec to enumerate network shares.^[27]
APT41	APT41 used the `net share` command as part of network reconnaissance.^[25]
Cobalt Strike	Cobalt Strike can query shared drives on the local system.^[9]
DarkVishnya	DarkVishnya scanned the network for public shared folders.^[26]
Dragonfly 2.0	Dragonfly 2.0 identified and browsed file servers in the victim network, sometimes , viewing files pertaining to ICS or Supervisory Control and Data Acquisition (SCADA) systems.^[20]^[21]
Empire	Empire can find shared drives on the local system.^[10]
InvisiMole	InvisiMole can gather network share information.^[11]
Koadic	Koadic can scan local network for open SMB.^[7]
Kwampirs	Kwampirs collects a list of network shares with the command `net share`.^[13]
MURKYTOP	MURKYTOP has the capability to retrieve information about shares on remote hosts.^[12]
Net	The `net view \remotesystem` and `net share` commands in Net can be used to find shared drives and directories on remote and local systems respectively.^[6]
Olympic Destroyer	Olympic Destroyer will attempt to enumerate mapped network shares to later attempt to wipe all files on those shares.^[17]
OSInfo	OSInfo discovers shares on the network^[15]
PlugX	PlugX has a module to enumerate network shares.^[16]
Pupy	Pupy can list local and remote shared drives and folders over SMB.^[8]
Ramsay	Ramsay can scan for network drives which may contain documents for collection.^[19]
ShimRat	ShimRat can enumerate connected drives for infected host machines.^[18]
Sowbug	Sowbug listed remote shared drives that were accessible from a victim.^[22]
Tropic Trooper	Tropic Trooper used `netview` to scan target systems for shared resources.^[24]
Zebrocy	Zebrocy identifies network drives when they are added to victim systems.^[14]

Mitigations

Mitigation	Description
Operating System Configuration	Enable Windows Group Policy "Do Not Allow Anonymous Enumeration of SAM Accounts and Shares" security setting to limit users who can enumerate network shares.^[5]

Detection

System and network discovery techniques normally occur throughout an operation as an adversary learns the environment. Data and events should not be viewed in isolation, but as part of a chain of behavior that could lead to other activities, such as Lateral Movement, based on the information obtained.

Normal, benign system and network events related to legitimate remote system discovery may be uncommon, depending on the environment and how they are used. Monitor processes and command-line arguments for actions that could be taken to gather system and network information. Remote access tools with built-in features may interact directly with the Windows API to gather information. Information may also be acquired through Windows system management tools such as Windows Management Instrumentation and PowerShell.

In cloud-based systems, native logging can be used to identify access to certain APIs and dashboards that may contain system information. Depending on how the environment is used, that data alone may not be sufficient due to benign use during normal operations.

Network Share Discovery

Procedure Examples

Mitigations

Detection

References