Know and understand scanning the storage media used to transfer data

4 – Networks and the Effects of Using Them

Objective

Know and understand how to scan storage media used to transfer data and why this is essential for network security, data integrity, legal compliance and health & safety (Cambridge IGCSE ICT 0417, AO 1‑3).

1. Why Scan Storage Media before Transfer?

• Prevent the spread of malware – viruses, ransomware, spyware and trojans can move from one computer to many via removable media.
• Detect corrupted or damaged files – bad sectors or incomplete writes can cause data loss or require retransmissions.
• Verify that the correct files are being transferred – avoid accidental sharing of personal or confidential data.
• Protect network performance – clean files reduce the need for error‑correcting retransmissions and minimise CPU/disk load on servers.
• Support wider network‑security policies – scanning is a frontline defence that complements firewalls, intrusion‑prevention systems and user‑access controls, helping to keep shared drives and LAN/WAN resources safe.
• Meet legal, ethical and e‑safety obligations – GDPR‑style data‑protection principles, school e‑safety policies and organisational compliance require documented scanning procedures (AO 3).

2. Common Types of Portable Storage Media

3. Scanning Technologies – What the Software Does

4. Step‑by‑Step Scanning Process

1. Connect the media to a trusted computer that has up‑to‑date anti‑virus/anti‑malware software and real‑time protection enabled.
2. Enable write protection – use a physical lock (e.g., SD‑card switch) or set the OS to read‑only mode.
3. Run a quick (signature‑based) scan to catch known threats immediately.
4. Run a full scan that includes heuristic, sandbox and AI‑driven analysis for unknown or suspicious files.
5. Check the file system for errors using built‑in utilities:
   • Windows: chkdsk /f /r
   • macOS: Disk Utility → First Aid
   • Linux: fsck -f
6. Verify file integrity (optional but recommended) – generate or compare checksums (MD5, SHA‑256) for critical files.
7. Interpret the scan results (see Decision Tree below).
8. Quarantine or delete any detected threats according to their severity.
9. Document the scan – date, media type, software/version, findings, actions taken (required for compliance).
10. Safely eject the media – use the OS “Eject” command; never remove while a scan or file transfer is in progress.

Interpreting Scan Alerts – Decision Tree

• Severity = High / Critical – automatically quarantine; do not transfer. Run a second scan with a different AV engine.
• Severity = Medium – quarantine, then review the file. If it is a trusted document (e.g., a school worksheet), verify the source before restoring.
• Severity = Low / Informational – note the finding. Most can be allowed after a visual inspection, but keep a record.
• False‑positive suspected – submit the file to the AV vendor’s “safe‑submit” portal and wait for confirmation before restoring.

5. How Scanning Fits into the Wider Network‑Security Strategy

Scanning removable media is a frontline defence that works together with:

• Firewalls that block unauthorised inbound traffic.
• Intrusion‑prevention/‑detection systems (IPS/IDS) that monitor network traffic for malicious patterns.
• Server‑side anti‑malware that protects shared drives, cloud storage and virtual machines.
• User‑access controls (password policies, least‑privilege) that limit what a compromised device can do.

By cleaning media before it enters the LAN/WAN, the risk of a single infected USB spreading to multiple workstations, servers or cloud services is dramatically reduced.

6. Effects of Scanning on Network Use

• Bandwidth preservation – clean files travel without needing retransmission caused by corrupted packets.
• Security of shared resources – scanned media protect network drives, cloud storage and servers from infection.
• Performance impact – full scans increase CPU and disk I/O; schedule them during off‑peak school hours or use “quick scan” for routine checks.
• Compliance & record‑keeping – documented scans satisfy school e‑safety policies, data‑protection legislation and Cambridge AO 3 requirements.

7. Legal, Ethical, e‑Safety and Data‑Protection Context

• Data‑protection principles – personal or sensitive data must be kept confidential, processed securely and transferred only with consent (e.g., GDPR‑style school policies). When the media contains personal data, the scan log must record the data type and the scan must follow the school’s Data Protection Policy.
• Credential‑stealing threats – malicious files can contain keyloggers or trojans that harvest passwords. Always verify the source of any executable before scanning and never run unknown programmes on a trusted computer.
• Copyright compliance – only transfer files you have the right to use. Copying commercial software, movies or music onto removable devices without permission breaches copyright law.
• e‑Safety responsibilities – teachers and pupils must avoid spreading malicious software, respect copyright and protect others’ data.
• Organisational policies (example)
  • Mandatory scanning of all removable media before use.
  • Retention of scan logs for at least 30 days.
  • Immediate reporting of high‑severity threats to IT staff.

8. Emerging Technology – AI‑Driven Scanning

Modern anti‑malware suites increasingly rely on cloud‑based machine‑learning models that can:

• Identify previously unseen ransomware families.
• Provide real‑time threat scores for each file.
• Reduce false‑positive rates through continuous model training.

When possible, enable “cloud‑assisted protection” on the scanning computer to benefit from the latest AI insights.

9. Physical Safety, Health and Ergonomic Considerations

• Safe handling of devices – always use the OS “Safely Remove Hardware” command; never pull a USB or SD card while a scan or transfer is running.
• Static‑electric discharge – ground yourself (e.g., touch a metal part of the desk) before handling removable media to avoid damaging sensitive electronics.
• Ergonomic tip – avoid repetitive plugging/unplugging of USB connectors; use a USB hub with a switch if many devices need to be checked.

10. Audience‑Specific Guidelines

11. Best Practices for All Users

• Keep anti‑virus definitions and operating‑system updates current.
• Use reputable, regularly updated scanning software (e.g., Windows Defender, Bitdefender, Sophos).
• Prefer network‑based transfers (cloud drives, school file‑share) where possible, but still scan any downloaded files.
• Maintain a backup of the original data before any repair or cleaning operation.
• Record scan details: date, media type, software/version, findings, actions taken.
• Educate peers about the dangers of “free” scanning tools that lack updates.
• When receiving a file via email, run the same scan process before opening or moving it to a USB drive.

12. Quick Revision Checklist

• Identify the type of storage media and its capacity.
• Know the scanning technologies available (signature, heuristic, sandbox, AI, real‑time).
• Recall the full process: connect → enable write‑protect → quick scan → full scan → file‑system check → integrity verification → interpret results → quarantine/delete → log → safe eject.
• Explain how scanning protects the network: security, bandwidth, performance, legal compliance.
• Apply audience‑specific guidelines (student vs. staff) and physical‑safety steps.
• Remember health/ergonomic tips and data‑protection legislation points.