Know and understand scanning the data/software when downloading

4 Networks and the Effects of Using Them

Objective

Know and understand scanning the data/software when downloading.

Why Scanning Is Required

• Protects the computer from viruses, worms, trojans and other malicious code.
• Prevents the spread of malware to other devices on the same network.
• Ensures the integrity of downloaded files – the file received is the file that was intended.
• Helps organisations comply with security policies and data‑protection regulations.

Common Threats Encountered When Downloading

1. Viruses – self‑replicating programs that can corrupt or delete data.
2. Worms – spread automatically across networks without user interaction.
3. Trojan horses – appear legitimate but contain hidden malicious functions.
4. Adware / Spyware – display unwanted ads or collect personal information.
5. Ransomware – encrypts files and demands payment for decryption.

Scanning Process – Step by Step

1. Initiate the download from a trusted source.
2. Save the file to a temporary folder rather than directly to the final location.
3. Launch the installed antivirus/anti‑malware program.
4. Select “Scan file” or “Scan folder” and point to the temporary location.
5. Review the scan results:
   • If the file is clean – move it to the intended folder.
   • If a threat is detected – delete or quarantine the file and report the incident.
6. Update the virus definition database before the next download.

Tools Frequently Used for Scanning

Tool	Type	Key Features
Windows Defender	Built‑in antivirus	Real‑time protection, cloud‑based updates, integration with Windows Explorer.
Malwarebytes	Anti‑malware	Specialised in removing adware, spyware and potentially unwanted programs.
ClamAV	Open‑source scanner	Command‑line interface, suitable for servers and automated scripts.
A \cdot G / Avast	Third‑party antivirus	Web shield, email scanning, scheduled scans.

Best Practices for Safe Downloading

• Only download software from the vendor’s official website or reputable app stores.
• Verify digital signatures or checksums (MD5, SHA‑256) when they are provided.
• Keep the operating system and all security software up to date.
• Enable real‑time scanning and automatic updates.
• Educate users about phishing emails and deceptive download links.
• Use a sandbox or virtual machine for testing unknown files before installing them on the main system.

Summary Table – Quick Reference

Action	When to Perform	Result Expected
Check source credibility	Before initiating any download	Reduced risk of malicious files.
Run a scan on the downloaded file	Immediately after download, before opening	Detection and removal of threats.
Verify checksum or digital signature	When provided by the publisher	Assurance that the file has not been altered.
Update virus definitions	Daily or as prompted by the security software	Protection against the latest malware.