Business leaders must be aware of several key cyber threats, including: 1. Phishing - Deceptive attempts to obtain sensitive information. 2. Ransomware - Malicious software that locks data until a ransom is paid. 3. Data Breaches - Unauthorized access to confidential information. 4. Insider Threats - Employees or associates who exploit their access for malicious purposes. 5. DDoS Attacks - Disruptions caused by overwhelming traffic to a network.