Indicator Removal on Host: Network Share Connection Removal

Adversaries may remove share connections that are no longer useful in order to clean up traces of their operation. Windows shared drive and Windows Admin Shares connections can be removed when no longer needed. Net is an example utility that can be used to remove network share connections with the net use \system\share /delete command. [1]

ID: T1070.005
Sub-technique of:  T1070
Tactic: Defense Evasion
Platforms: Windows
System Requirements: Established network share connection to a remote system. Level of access depends on permissions of the account used.
Permissions Required: Administrator, User
Data Sources: Authentication logs, Packet capture, Process command-line parameters, Process monitoring
Defense Bypassed: Host forensic analysis
Version: 1.0
Created: 31 January 2020
Last Modified: 31 January 2020

Procedure Examples

Name Description
InvisiMole

InvisiMole can disconnect previously connected remote drives.[2]

Net

The net use \system\share /delete command can be used in Net to remove an established connection to a network share.[1]

RobbinHood

RobbinHood disconnects all network shares from the computer with the command net use * /DELETE /Y.[3]

Threat Group-3390

Threat Group-3390 has detached network shares after exfiltrating files, likely to evade detection.[4]

Mitigations

This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features.

Detection

Network share connections may be common depending on how an network environment is used. Monitor command-line invocation of net use commands associated with establishing and removing remote shares over SMB, including following best practices for detection of Windows Admin Shares. SMB traffic between systems may also be captured and decoded to look for related network share session and file transfer activity. Windows authentication logs are also useful in determining when authenticated network shares are established and by which account, and can be used to correlate network share activity to other events to investigate potentially malicious activity.

References