The TOR activity detection identifies the use of TOR (The Onion Router) network services within an organization's network. While TOR can be used for legitimate purposes, it is often employed by malicious actors to anonymize their activities, including data exfiltration, command and control (C2) communication, and accessing unauthorized content. Detecting TOR activity is crucial for identifying potential security threats and preventing misuse of anonymization services.
Scenario 1: An internal host establishes multiple outbound connections to known TOR entry nodes. Investigation reveals that the host is compromised, and the attacker is using TOR to anonymize C2 communications and exfiltrate data.
Scenario 2: A sudden increase in encrypted network traffic is detected, with connections to uncommon IP addresses. Further analysis indicates that a security researcher within the organization was using TOR for legitimate testing purposes, causing the detection to trigger.
If this detection indicates a genuine threat, the organization faces significant risks:
TOR activity can be used to exfiltrate sensitive data from the organization, leading to potential financial and reputational damage.
Attackers can use TOR to maintain anonymity, making it difficult to trace their actions and preventing timely threat response.
Unauthorized use of TOR may violate company policies and regulatory requirements, leading to compliance issues.
Review logs for connections to known TOR entry nodes and IP addresses associated with the TOR network. Focus on identifying the source of the TOR activity.
Determine the internal host generating the TOR traffic. Verify if the host and user are authorized to use TOR.
Look for other signs of compromise or related suspicious behavior, such as unusual data transfers, malware alerts, or unauthorized access attempts.
Confirm if any legitimate research, testing, or authorized use of TOR could explain the detected activity.