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Network Share Discovery

Networks often contain shared network drives and folders that enable users to access file directories on various systems across a network.

Windows

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.

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.

Mac

On Mac, locally mounted shares can be viewed with the df -aH command.

ID: T1135

Tactic: Discovery

Platform:  macOS, Windows

Permissions Required:  User

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

Version: 1.0

Examples

NameDescription
Cobalt Strike

Cobalt Strike can query shared drives on the local system.[3]

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.[4][5]

InvisiMole

InvisiMole can gather network share information.[6]

Koadic

Koadic can scan local network for open SMB.[7]

Kwampirs

Kwampirs collects a list of network shares with the command net share.[8]

MURKYTOP

has the capability to retrieve information about shares on remote hosts.[9]

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.[10]

OSInfo

OSInfo discovers shares on the network[11]

Pupy

Pupy can list local and remote shared drives and folders over SMB.[12]

Sowbug

Sowbug listed remote shared drives that were accessible from a victim.[13]

Mitigation

Identify unnecessary system utilities or potentially malicious software that may be used to acquire network share information, and audit and/or block them by using whitelisting [14] tools, like AppLocker, [15] [16] or Software Restriction Policies [17] where appropriate. [18]

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.

References