Threat Hunting
Threat hunting is a proactive cybersecurity approach aimed at identifying and mitigating potential threats within an organization's network or systems. It involves actively searching for signs of malicious activity or security breaches that may have evaded traditional security measures. Threat hunters analyze data, investigate anomalies, and employ various techniques to detect and neutralize threats before they cause damage. This continuous process helps organizations stay ahead of evolving cyber threats and strengthen their overall security posture.
Several signs may indicate that your network is compromised:
Unusual Network Activity: Unexplained spikes in network traffic or unexpected data transfers could indicate unauthorized access or data exfiltration.
Strange System Behavior: Unusual activities on individual systems such as frequent crashes, unexplained file modifications, or unauthorized software installations may indicate compromise.
Anomalies in Logs: Reviewing system and network logs for unusual or suspicious activities can help identify potential compromises.
Antivirus Alerts: Alerts from antivirus or endpoint detection and response (EDR) systems indicating the presence of malware or suspicious behavior should be investigated promptly.
Unauthorized Access Attempts: Failed login attempts, brute force attacks, or access to sensitive systems or data by unauthorized users are red flags.
Unexplained System Modifications: Changes to system configurations, permissions, or the presence of unknown files or processes may indicate compromise.
Unsolicited Communication: Unexpected emails, messages, or phone calls requesting sensitive information or prompting actions could be part of a phishing or social engineering attack.
System Performance Issues: Sudden degradation in system performance, such as slower response times or increased CPU/memory usage, may be caused by malware or other malicious activities.
Regular monitoring, threat intelligence integration, and comprehensive security policies can help detect and respond to network compromises effectively. Employing security measures such as firewalls, intrusion detection systems (IDS), and endpoint protection solutions can also enhance your network's resilience against potential threats. Additionally, conducting periodic security assessments and penetration tests can help identify vulnerabilities and strengthen your network's defenses.
Hunting for Threats Via CVEs
As part of a threat hunting investigation, a researcher may want to look for
related published reports, such as threat intel reports and CVEs.
CVE (Common Vulnerabilities and Exposures) is a list of identifiers for
publicly known cybersecurity vulnerabilities. Looking for known and widely
used vulnerabilities may help detect an active breach.
CVE includes information about the vulnerability, how it is used, and
sometimes techniques used to detect and mitigate it. A threat hunter can
use this information to track down hackers exploiting the vulnerability in
the company’s environment, by looking for related evidence in logs.
What is an Indicator of Compromise (IOC)
Indicators of Compromise (IOCs) are traces or artifacts left behind by malicious activities that indicate a potential security breach. These indicators serve as clues for cybersecurity professionals to detect, investigate, and respond to security incidents. Common IOCs include:
Malware Signatures: Unique patterns or characteristics of malicious code identified through antivirus scans or malware analysis.
Anomalous Network Traffic: Unusual patterns in network communications, such as unexpected connections, unusual port usage, or high volumes of data transfers.
Unauthorized Access Attempts: Failed login attempts, brute force attacks, or suspicious activity indicating unauthorized access to systems or accounts.
Unusual File or System Modifications: Changes to system files, configurations, or permissions that deviate from normal operations, such as file deletions, registry changes, or new user accounts.
Abnormal System Behavior: Unexplained system crashes, slowdowns, or other unusual activities that may indicate malware presence or compromise.
Phishing Indicators: Suspicious emails, URLs, or attachments that attempt to trick users into disclosing sensitive information or downloading malware.
Command and Control (C2) Communications: Outbound connections to known malicious IP addresses or domains associated with command-and-control servers used by malware.
Security Alerts: Warnings or notifications generated by security tools, such as intrusion detection systems (IDS), antivirus software, or security information and event management (SIEM) systems.
Privilege Escalation Attempts: Unauthorized attempts to elevate user privileges or access restricted resources within the network.
Suspicious User Behavior: Abnormal user activities, such as accessing unusual files or directories, downloading large amounts of data, or accessing sensitive information outside of normal work hours.
By monitoring and analyzing these indicators, organizations can proactively identify and respond to security incidents, mitigate risks, and strengthen their overall cybersecurity posture.