The Hafnium (HF) cyberattack targeted Microsoft Exchange, exploiting vulnerabilities like SSRF and insecure deserialization, affecting ~350 million mailboxes. Attackers bypassed authentication to gain SYSTEM access, deploy Web Shells (e.g., China Chopper), and exfiltrate sensitive data. The attackers exploited vulnerabilities CVE-2021-26855, CVE-2021-26857, CVE-2021-26858, and CVE-2021-27065 to escalate privileges and move laterally within networks. Happiest Minds' Cyber Security Incident Response Team (CSIRT) analyzed and responded, emphasizing proactive defenses such as Zero Trust, advanced detection, and continuous testing to mitigate such incidents.

Join for free to read