Intrusion
Intrusion, in the mainframe context, refers to any unauthorized attempt or successful act of gaining access to z/OS system resources, data, or applications without the necessary permissions. This typically involves bypassing established security controls to compromise the confidentiality, integrity, or availability of critical enterprise assets.
Key Characteristics
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- Targeted Resources: Often focuses on sensitive data in
VSAMfiles,DB2tables,IMSdatabases,CICStransactions, or privileged system utilities and commands. - Methods of Attack: Can range from exploiting weak
RACF,ACF2, orTop Secretprofiles, social engineering, leveraging unpatched vulnerabilities in z/OS or middleware, to unauthorized physical access. - Impact: Leads to potential data breaches, data corruption, system disruption, denial of service, financial loss, and severe regulatory non-compliance issues.
- Detection Mechanisms: Primarily identified through analysis of
SMFrecords, system logs, security information and event management (SIEM) systems, and specialized mainframe intrusion detection tools. - Prevention Focus: Relies heavily on robust access control systems, strong authentication, regular security audits, and diligent patch management for z/OS and its subsystems.
- Targeted Resources: Often focuses on sensitive data in
Use Cases
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- An external attacker attempting to access sensitive customer data stored in a
DB2database orVSAMdataset by exploiting a misconfiguredRACFprofile. - An internal user attempting to execute a
JCLjob that updates production data without having the requiredACF2permissions for that dataset or program. - A compromised
CICStransaction allowing an unauthorized user to perform financial transactions or modify critical application parameters. - Exploiting a known vulnerability in a legacy
COBOLapplication to gain elevated privileges within the z/OS environment.
- An external attacker attempting to access sensitive customer data stored in a
Related Concepts
Intrusion is fundamentally countered by Access Control Systems like RACF, ACF2, and Top Secret, which define and enforce user authorizations. SMF Records are crucial for logging all system and security events, providing the audit trail necessary to detect and investigate potential intrusions. It directly threatens System Integrity and Data Confidentiality, making robust security practices, including Encryption and Security Auditing, essential components of a secure mainframe environment.
- Principle of Least Privilege: Grant users only the minimum
RACF/ACF2/Top Secretaccess rights required to perform their job functions. - Strong Authentication: Implement multi-factor authentication (MFA) for privileged users and critical access points like
TSOandOMVS. - Regular Security Audits: Periodically review
RACFprofiles,SMFdata, and system configurations for weaknesses, unauthorized access attempts, and compliance. - Patch Management: Keep z/OS, middleware (e.g.,
CICS,DB2,IMS), and third-party software up-to-date with the latest security patches and fixes (APARs). - Security Monitoring: Implement real-time monitoring of
SMFrecords, system logs, and network traffic for suspicious activities and potential intrusion attempts. - Incident Response Plan: Develop and regularly test a comprehensive incident response plan specifically for mainframe security breaches.