Network Intrusion Prevention Systems

A subject can access the web with an organization device.

A subject is able to access external FTP servers.

A subject is able to access external SSH servers.

A subject conducts a scan of a network to identify additional systems, or services running on those systems.

The subject installs and uses an unapproved VPN client, potentially violating organizational policy. By using a VPN service not controlled by the organization, the subject can bypass security controls, reducing the security team’s visibility into network activity conducted through the unauthorized VPN. This could lead to significant security risks, as monitoring and detection mechanisms are circumvented.

The subject initiates configuration or usage of Remote Desktop Protocol (RDP) to enable remote control of an endpoint or server, typically for purposes not sanctioned by the organization. This activity may include enabling RDP settings through system configuration, altering firewall rules, adding users to RDP groups, or initiating browser-based remote access sessions. While RDP is commonly used for legitimate administrative and support purposes, its unauthorized configuration is a well-documented preparatory behavior preceding data exfiltration, sabotage, or persistent unauthorized access.

RDP can be enabled through local system settings, remote management tools, or even web-based services that proxy or tunnel RDP traffic through HTTPS. Subjects may configure RDP access for themselves, for a secondary device, or to facilitate third-party (external) involvement in insider threat activities.

The subject intentionally weakens or bypasses network security controls for a third party, such as providing credentials or disabling security controls.

A subject may employ a Python-based listening service to exfiltrate organizational data, typically as part of a self-initiated or premeditated breach. Python’s accessibility and versatility make it a powerful tool for creating custom scripts capable of transmitting sensitive data to external or unauthorized internal systems.

In this infringement method, the subject configures a Python script—often hosted externally or on a covert internal system—to listen for incoming connections. A complementary script, running within the organization’s network (such as on a corporate laptop), transmits sensitive files or data streams to the listening service using common protocols such as HTTP or TCP, or via more covert channels including DNS tunneling, ICMP, or steganographic methods. Publicly available tools such as PyExfil can facilitate these operations, offering modular capabilities for exfiltrating data across multiple vectors.

Examples of Use:

• A user sets up a lightweight Python HTTP listener on a personal VPS and writes a Python script to send confidential client records over HTTPS.
• A developer leverages a custom Python socket script to transfer log data to a system outside the organization's network, circumventing monitoring tools.
• An insider adapts an open-source exfiltration framework like PyExfil to send data out via DNS queries to a registered domain.

Detection Considerations:

• Monitor for local Python processes opening network sockets or binding to uncommon ports.
• Generate alerts on outbound connections to unfamiliar IP addresses or those exhibiting anomalous traffic patterns.
• Utilize endpoint detection and response (EDR) solutions to flag scripting activity involving file access and external communications.
• Inspect Unified Logs, network flow data, and system audit trails for signs of unauthorized data movement or execution of custom scripts.

The subject installs and operates unauthorized cryptocurrency mining software on organizational systems, leveraging compute, network, and energy resources for personal financial gain. This activity subverts authorized system use policies, degrades operational performance, increases attack surface, and introduces external control risks.

Characteristics

• Deploys CPU-intensive or GPU-intensive processes (e.g., xmrig, ethminer, phoenixminer, nicehash) on endpoints, servers, or cloud infrastructure without approval.
• May use containerized deployments (Docker), low-footprint mining scripts, browser-based JavaScript miners, or stealth binaries disguised as legitimate processes.
• Often configured to throttle resource usage during business hours to evade human and telemetry detection.
• Establishes persistent outbound network connections to mining pools (e.g., via Stratum mining protocol over TCP/SSL).
• Frequently disables system security features (e.g., Anti-Virus (AV)/Endpoint Detection & Response (EDR) agents, power-saving modes) to maintain uninterrupted mining sessions.
• Represents not only misuse of resources but also creates unauthorized outbound communication channels that bypass standard network controls.

Example Scenario

A subject installs a customized xmrig Monero mining binary onto under-monitored R&D servers by side-loading it via a USB device. The miner operates in "stealth mode," hiding its process name within legitimate system services and throttling CPU usage to 60% during business hours. Off-peak hours show 95% CPU utilization with persistent outbound TCP traffic to an external mining pool over a non-standard port. The mining operation remains active for six months, leading to significant compute degradation, unplanned electricity costs, and unmonitored external network connections that could facilitate broader compromise.

The subject initiates configuration changes to enable Remote Desktop Protocol (RDP) or Remote Assistance on a Windows system, typically through the System Properties dialog, registry modifications, or local group policy. This behavior may indicate preparatory actions to grant unauthorized remote access to the endpoint, whether to an external actor, co-conspirator, or secondary account.

Characteristics

Subject opens the Remote tab within the System Properties dialog (SystemPropertiesRemote.exe) and enables:

• Remote Assistance
  Remote Desktop

May configure additional RDP-related settings such as:

• Allowing connections from any version of RDP clients (less secure)
  Adding specific users to the Remote Desktop Users group
  Modifying Group Policy to allow RDP access

Often accompanied by:

• Firewall rule changes to allow inbound RDP (TCP 3389)
  Creation of local accounts or service accounts with RDP permissions
  Disabling sleep, lock, or idle timeout settings to keep the system continuously accessible

In some cases, used to stage access prior to file exfiltration, remote control handoff, or backdoor persistence.

Example Scenario

A subject accesses the Remote tab via SystemPropertiesRemote.exe and enables Remote Desktop, selecting the “Allow connections from computers running any version of Remote Desktop” option. They add a personal email-based Microsoft account to the Remote Desktop Users group. No help desk ticket or change request is submitted. Over the following days, successful RDP logins are observed from an IP address outside of corporate VPN boundaries, correlating with a data transfer spike.