| Audit Type |   Reason  | 
| New System Installation Security Audits | 
  Ensure conformance to existing policies and a standard system configuration.  | 
| Regular Automated System Audit Checks | 
  Reveal a "visitation" by an intruder or illicit activity by insiders.  | 
| Random Security Audit Checks | 
  
 
 -  Test for conformance to security policies and standards (by finding illicit activity) , 
 
 -  Check for the existence of a specific class of problems (e.g., the presence of a vulnerability reported by a vendor). 
 
    | 
| Nightly Audits of Critical Files | 
  
 -  Assess the integrity of critical files (e.g., the password file) 
 
 -  Integrity of databases (e.g., payroll or sales and marketing information). 
   | 
 | User Account Activity Audits | 
  Detect dormant, invalid, misused accounts.  | 
| Periodic audits and vulnerability assessments  | 
  Determine overall state of your security infrastructure.  |