Brad Christian

Brad Christian

Senior Search Engine Optimization Specialist

Published

Understanding IoAs

In cybersecurity, indicators of attack (IoAs) are signs or pieces of evidence that signifies an attacker is actively attempting to compromise a system or network. They focus on the intent and actions of the attacker instead of the specific tools or malware used. This focus on attacker behavior highlights the adversary's tactics, techniques, and procedures (TTPs) while looking for patterns and sequences of events that indicate malicious intent.

Examples of IoAs

There are numerous IoAs that can be used to determine if an attack is underway. Some examples include:

  • Suspicious network traffic: Often visible as communication between internal hosts and known malicious or unusual external destinations. Can also present as lateral movement within the network or sudden spikes in traffic, especially to non-standard ports.
  • Unusual login activity: Compromised credentials or brute-force attacks can show as multiple failed login attempts, especially if they occur from different geographic locations or at odd hours.
  • Command execution: The running of unusual scripts, commands, or processes on the network can be a sign of attack.
  • Anomalous file activity: Unauthorized access to files, mass file downloads, or abnormal file modifications can all be signs of an attack.
  • Privilege escalation attempts: Attackers often seek to gain access to higher-level systems or data during attacks to exfiltrate more valuable, sensitive data.
  • Malware reinfection: Repeated reinfection of a system shortly after malware is removed could indicate an advanced persistent threat (APT).

Key Differences Between IoA and IoC

There are fundamental differences between IoAs and indicators of compromise (IoCs). First, IoAs are proactive while IoCs are reactive. IoAs aim to detect and stop attacks in progress while IoCs focus on identifying breaches that have already occurred.

Additionally, IoAs focus on intent and behavior while IoCs focus on technical signs of compromise. That means that IoAs are more about the attacker and their motivations, while IoCs look at technical details of the breach, such as malware signatures and IP addresses.

Importance of IoAs in Cybersecurity

IoAs are of critical importance for identifying potential attacks on a network or application. These important benefits include:

  • Early threat detection: Allows for faster and more effective response due to reduced time to identifying attacks.
  • Reduced dwell time: Early detection helps limit the amount of time an attacker has within the network.
  • Defense against evolving threats: Even if IoCs are not known for new and sophisticated attacks, IoAs can help identify an attempted attack in progress.
  • Improved incident response: Valuable context and actionable information for security teams helps improve their investigation and response.

Advantages and Disadvantages of Using IoAs

There are numerous advantages and disadvantages to leveraging IoAs in your cybersecurity strategy. Some examples of each include:

Advantages

  • Proactive defense: Taking a proactive approach to cybersecurity can help stop attacks before they become full breaches.
  • Focus on attacker intent: Emphasis on the attacker's TTPs can help security teams understand the goals and intentions of the adversary, helping them stay ahead of the attack.
  • Enhanced security posture: By enabling early threat detection, faster response times, and the ability to adapt to evolving threats, IoAs contribute to a more robust overall security posture.

Disadvantages

  • Data volume: Leveraging IoAs often requires analyzing large volumes of data, potentially impacting system performance and requiring significant processing and storage resources.
  • False positives: Alert fatigue and wasted resources are risks of using anomaly-based detection systems for IoAs.
  • Limited forensic value: IoAs are geared toward early detection, limiting their forensic value when compared to IoCs. Focusing solely on IoAs makes it difficult to reconstruct a full attack timeline and impact after a breach.

How NETSCOUT Helps

NETSCOUT's Omnis Cyber Intelligence leverages the MITRE ATT&CK Framework to map IoAs to adversary TTPs. By mapping adversary TTPs to a well-known knowledge base, Omnis Cyber Intelligence can help detect attempted attacks and provide valuable context around the methodologies being leveraged. It also detects all connection attempts in and out of the network, helping discover abnormal connections to potentially or known malicious networks. Rooted in patented deep packet inspection (DPI) at scale technology, comprehensive and scalable visibility across all areas of the network is possible with Omnis Cyber Intelligence.