Indicator Removal: Clear Network Connection History and Configurations

Adversaries may clear or remove evidence of malicious network connections in order to clean up traces of their operations. Configuration settings as well as various artifacts that highlight connection history may be created on a system and/or in application logs from behaviors that require network connections, such as Remote Services or External Remote Services. Defenders may use these artifacts to monitor or otherwise analyze network connections created by adversaries.

Network connection history may be stored in various locations. For example, RDP connection history may be stored in Windows Registry values under [1]:

  • HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client\Default
  • HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client\Servers

Windows may also store information about recent RDP connections in files such as C:\Users\%username%\Documents\Default.rdp and C:\Users\%username%\AppData\Local\Microsoft\TerminalServer Client\Cache\.[2] Similarly, macOS and Linux hosts may store information highlighting connection history in system logs (such as those stored in /Library/Logs and/or /var/log/).[3][4][5]

Malicious network connections may also require changes to third-party applications or network configuration settings, such as Disable or Modify System Firewall or tampering to enable Proxy. Adversaries may delete or modify this data to conceal indicators and/or impede defensive analysis.

ID: T1070.007
Sub-technique of:  T1070
Tactic: Defense Evasion
Platforms: Linux, Network Devices, Windows, macOS
Contributors: CrowdStrike Falcon OverWatch
Version: 1.2
Created: 15 June 2022
Last Modified: 16 April 2025

Procedure Examples

ID Name Description
C0056 RedPenguin

During RedPenguin, UNC3886 used an implant to delete logs associated with unauthorized access to targeted Junos OS devices.[6]

S0559 SUNBURST

SUNBURST also removed the firewall rules it created during execution.[7]

G1048 UNC3886

UNC3886 has cleared specific events that contained the threat actor’s IP address from multiple log sources.[8]

G1017 Volt Typhoon

Volt Typhoon has inspected server logs to remove their IPs.[9]

Mitigations

ID Mitigation Description
M1029 Remote Data Storage

Automatically forward events to a log server or data repository to prevent conditions in which the adversary can locate and manipulate data on the local system. When possible, minimize time delay on event reporting to avoid prolonged storage on the local system.

M1024 Restrict Registry Permissions

Protect generated event files and logs that are stored locally with proper permissions and authentication and limit opportunities for adversaries to increase privileges by preventing Privilege Escalation opportunities.

Detection Strategy

ID Name Analytic ID Analytic Description
DET0049 Behavioral Detection of Network History and Configuration Tampering AN0133

Detects attempts to clear RDP/network history and modify network configuration artifacts through command execution, registry key deletion, firewall rule changes, and suspicious file deletions (e.g., Default.rdp, registry edits to Terminal Server Client keys).

AN0134

Detects deletion or overwriting of logs/configs that store SSH or proxy activity, such as /var/log/auth.log or custom .bash_history clearing tied to SSH sessions or firewall rule changes.

AN0135

Detects removal of Remote Login or Screen Sharing logs in Unified Logging, deletion of com.apple.UTun, or suspicious Terminal use of rm, sudo pfctl -F all to clear network state/config history.

AN0136

Detects firewall rule modifications or reset of logs/connection tables (e.g., clear logging, erase startup-config, write erase) following remote access activity on routers, switches, or VPN appliances.

References