First, let us define the endpoint Tripwires is a subject who installs custom software or malware on an endpoint, potentially disguising it as a legitimate process. This software includes tripwire logic to monitor the system for signs of security activity.
What can this technique do?
The tripwire software monitors various aspects of the endpoint to detect potential investigations:
- Security Tool Detection: It scans running processes and monitors new files or services for signatures of known security tools, such as antivirus programs, forensic tools, and Endpoint Detection and Response (EDR) systems.
- File and System Access: It tracks access to critical files or system directories (e.g., system logs, registry entries) commonly accessed during security investigations. Attempts to open or read sensitive files can trigger an alert.
- Network Traffic Analysis: The software analyzes network traffic to identify unusual patterns, including connections to Security Operations Centers (SOC) or the blocking of command-and-control servers by network security controls.
- User and System Behavior: It observes system behavior and monitors logs (such as event logs) that indicate an investigation is in progress, such as switching to an administrative account or modifying security settings (e.g., enabling disk encryption, changing firewall rules).
How can threat actors abuse this software for their own interests?
Upon detecting security activity, the threat actors can abuse the tripwire and initiate various evasive responses:
- Alert the Subject: It covertly sends an alert to an external server controlled by the subject, using common system tools (e.g., curl, wget, or HTTP requests).
- Modify Endpoint Behavior: It can terminate malicious processes, erase evidence (e.g., logs, browser history, specific files), or restore system and network configurations to conceal signs of tampering.
Here is the Scenario of an attack by Endpoint tripwires:
Phase 1: Initial Access and Persistence The threat actors gain initial access through a phishing campaign, delivering a trojanized document to an employee. Once the document is opened, malware is executed, creating a foothold on the endpoint. The malware installs a Remote Access Trojan (RAT) and establishes persistence using scheduled tasks.
Phase 2: Implantation of Endpoint Tripwires Knowing that the organization uses an EDR solution, the attackers employ an endpoint tripwire as an anti-forensics technique. They strategically place scripts and lightweight sensors on the compromised machine that monitor the EDR process and other security tools.
- Tripwire Activation: The tripwire detects any attempt to scan, quarantine, or remove malware files, as well as any attempts to inspect suspicious activities such as memory dumps or sandboxing.
- Triggered Action: If the EDR or any other security tool attempts to interact with malicious files or processes, the tripwire immediately triggers an action.
++and for your information This will ensure that the security operation center (SOC) team either sees nothing or is presented with false evidence, slowing their investigation.
Phase 3: Data Exfiltration With endpoint tripwires in place, the threat actors can continue their malicious activity under the radar. They move laterally across the network, collecting sensitive data. Any time a security solution attempts to inspect an endpoint involved in the attack, the tripwires cloak malicious behavior and ensure the security team's response is delayed or misdirected.
- Example: The attackers use command and control (C2) infrastructure that leverages encrypted communications. The EDR flags abnormal traffic, but the tripwires alter network logs to make it look like normal traffic, masking the exfiltration attempts.
and we know what the final stage will be :-
Phase 4: Cleanup and Disruption Once the data has been successfully exfiltrated, the attackers activate the tripwires one last time to erase forensic evidence of the attack. They delete logs, change file access timestamps, and overwrite data remnants that could help the incident response team trace the attack path.
now let's suggest "Prevention" and "Detection" Actions can help catch this kind of attacks :
Prevention Mechanisms :
- Application Whitelisting By only allowing pre-approved software to be installed and run on corporate devices, the subject is unable to install software themselves.
- Restrict Access to Administrative Privileges The Principle of Least Privilege should be enforced, and period reviews of permissions conducted to ensure that accounts have the minimum level of access required to complete duties as per their role.
and more more ... plz feel free to add more.
Detection Mechanisms
- Deep Packet Inspection Implement Deep Packet Inspection (DPI) tools to inspect the content of network packets beyond the header information. DPI can identify unusual patterns and hidden data within legitimate protocols. DPI can be conducted with a range of software and hardware solutions, such as Unified Threat Management (UTM) and Next-Generation Firewalls (NGFWs), as well as Intrusion Detection and Prevention Systems (IDPS) such as Snort and Suricata,?
- Agent Capable of Endpoint Detection and Response An agent capable of Endpoint Detection and Response (EDR) is a software agent installed on organization endpoints (such as laptops and servers) that (at a minimum) records the Operating System, application, and network activity on an endpoint. Typically, EDR operates in an agent/server model, where agents automatically send logs to a server, where the server correlates those logs based on a rule set. This rule set is then used to surface potential security-related events, that can then be analyzed. An EDR agent typically also has some form of remote shell capability, where a user of the EDR platform can gain a remote shell session on a target endpoint, for incident response purposes. An EDR agent will typically have the ability to remotely isolate an endpoint, where all network activity is blocked on the target endpoint (other than the network activity required for the EDR platform to operate).
- PowerShell Logging Detailed PowerShell logging is not enabled by default and must be configured PowerShell is able to record the processing of commands, script blocks, functions, and scripts, whether invoked interactively, or through automation. These can be reviewed as Windows Event logs to the PowerShell Core/Operational log as Event ID 4104.
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