Security: a practical CompTIA A+ guide
Identity, malware response, wireless defense, and risk reduction. Learn the mental models, common failure modes, and evidence-based troubleshooting steps.
01. Authentication and authorization
Authentication proves identity; authorization determines access. MFA requires different factor categories, not merely two passwords. Least privilege reduces blast radius; password managers support unique credentials; privileged accounts should have tighter control. Zero Trust requires explicit verification based on context, not automatic trust from being inside the office.
02. Threat recognition
Phishing seeks credentials or actions through deception. Smishing uses SMS; vishing uses voice calls. Ransomware encrypts or blocks data; credential theft may not have obvious signs. Suspicious USB drives should follow handling policy, never be plugged into a production machine to identify an owner.
03. Response sequence
For suspected compromise, follow organizational response policy: identify/report, isolate when instructed and authorized, preserve relevant evidence, contain and eradicate through approved procedures, then recover and monitor. Do not destroy logs, wipe systems prematurely, or promise restoration without checking backup integrity.
04. Protection layers
Use timely updates, endpoint protection, firewalls, device encryption, secure Wi-Fi, backups, and training. WPA3 is stronger than WEP; BitLocker protects Windows data at rest but does not replace access controls or backups. Verify recovery keys are stored through approved processes.
Apply the lesson: real support cases
A user is asked to approve an unexpected MFA push repeatedly. Treat it as suspicious, deny the request, and report it through policy.
A laptop is stolen but the drive was encrypted. Validate recovery-key custody and incident reporting; encryption reduces data exposure but does not mean the event goes undocumented.
These are original explanatory notes aligned to the named exam domains; review the current official objectives for exact scope. The mock exam is practice only and is not scored on CompTIA's scale.