Dual-tier client and server inspection
Runs fast pre-flight heuristics in your browser before streaming directly to isolated sandbox memory for deep antivirus signature validation.
File Security & Malware Scanner
Free online file security scanner. Analyze documents, PDFs, executables, and archives for hidden viruses, VBA macros, webshells, decompression bombs, and disguised binaries.
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How to use File Security & Malware Scanner
- 1
Drag and drop any file or click "Select File to Scan" to upload (supports up to 25 MB).
- 2
The scanner executes instant in-browser pre-flight checks (magic bytes, SHA-256 fingerprint, entropy calculation).
- 3
The file is streamed directly in memory to the hardened sandbox engine for deep heuristics, PDF exploit checks, VBA macro inspection, and antivirus signature matching.
- 4
Review the comprehensive 6-pillar security report card, risk index (0–100), and cryptographic hash fingerprints.
Why use this tool?
Detects disguised binaries & polyglots
Analyzes true file magic bytes (Windows PE MZ, Linux ELF, Mach-O) to catch malicious executables camouflaged as innocent PDFs or images.
Zero disk persistence & memory streaming
Uploaded files are analyzed in temporary memory buffers and streamed via socket to ClamAV without being permanently stored or logged.
Frequently asked questions
Can this tool guarantee that a scanned file is 100% safe?
No automated scanner can guarantee 100% detection of all zero-day exploits, emerging polymorphic malware, or targeted APT attacks. A clean verdict indicates that no known virus signatures, macro exploits, or dangerous script streams matched at scan time. Users must maintain active endpoint antivirus protection and exercise zero-trust caution.
What file types are supported?
UsefulGo File Security Scanner supports all common formats including PDF, Word (.docx, .doc, .docm), Excel (.xlsx, .xlsm), PowerPoint, ZIP archives, images (.png, .jpg, .svg), executable binaries (.exe, .dll, .elf), and scripts (.sh, .ps1, .php, .js) up to 25 MB.
Are my uploaded files retained on your servers?
No. Files are analyzed strictly in volatile memory (RAM) within isolated containers and discarded immediately after the scan completes. UsefulGo does not retain, index, or archive scanned files.
How does the zip bomb detection work?
The scanner inspects archive central directory headers without full extraction. If the uncompressed-to-compressed ratio exceeds safe thresholds (> 50:1) or total uncompressed volume exceeds 100 MB, the file is flagged as an expansion bomb (Denial of Service attack).
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