Dangerous Downloads

Why Downloads Are Risky

Downloading files is one of the most common ways malware reaches your computer. Attackers hide viruses, ransomware, and spyware inside files that look harmless or useful.

High-Risk File Types

Some file types are more dangerous than others:

• .exe, .msi (Windows installers): Can run any code on your computer
• .js, .vbs, .bat, .cmd (scripts): Execute commands automatically
• .zip, .rar with executables inside: Attackers hide malware in archives
• .docm, .xlsm (Office files with macros): Can run malicious code when opened
• .iso, .img (disk images): Often used to bypass security filters

Warning: Windows hides file extensions by default. A file named "photo.jpg.exe" may appear as "photo.jpg" but is actually an executable.

Safe Download Sources

Only download software from trusted sources:

• Official vendor websites (check the URL carefully)
• Official app stores (Microsoft Store, Mac App Store)
• Reputable software repositories (GitHub releases from verified developers)

Avoid:

• "Free download" sites that bundle unwanted software
• Torrent sites and file-sharing networks
• Links in unsolicited emails or messages
• Pop-up ads offering free software

Warning Signs Before Downloading

• The website looks unprofessional or has many pop-up ads
• The download button is hard to find among fake buttons
• The file name does not match what you expected
• The file size seems wrong (a simple utility should not be 500MB)
• Your browser shows a warning about the download

After Downloading

Before opening any downloaded file:

1. Check the file extension (enable "show file extensions" in your OS)
2. Scan the file with your security software
3. If it is a .zip or .rar, inspect the contents before extracting
4. Be suspicious if the file asks for administrator privileges

What If You Downloaded Something Bad?

• Do not open or run the file
• Delete it immediately (empty your recycle bin too)
• Run a full security scan
• If you already ran the file, disconnect from the internet and scan from a clean device

Key Takeaways

• Only download from official sources
• Be suspicious of free software from unknown sites
• Check file extensions before opening
• Scan downloads before running them
• Trust your browser's download warnings