File Reputation Analysis

How File Analysis Works

The implementation follows a two-stage process.

1. Calculate the uploaded file's SHA-256 hash.
2. Query VirusTotal for an existing report associated with that hash.

If the report cannot be retrieved because of a VirusTotal API error, the implementation attempts to upload the file for scanning.

Running a File Analysis

1. Open VerAI.
2. Select a file using the file upload field.
3. Submit the analysis.
4. Wait for the response.
5. Review the returned VirusTotal information.

The implementation reads the uploaded file's contents for hashing and possible submission.

SHA-256 Identification

SHA-256 produces a 256-bit digest.

VerAI uses this digest to identify files when requesting existing VirusTotal records.

Example

The SHA-256 hash of the text hello is:

2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824

The actual digest depends on the exact file contents.

Even a one-byte difference generally produces a different digest.

Existing VirusTotal Reports

If an existing record is found, VerAI returns the information provided by the VirusTotal API.

Depending on the returned record, the information may include:

• File hashes
• File metadata
• Security vendor detections
• Analysis statistics
• Reputation information
• Other VirusTotal attributes

The content depends on the provider's API and available data.

Files Without an Existing Report

When the report lookup raises a VirusTotal API error, the implementation attempts to submit the uploaded file using the VirusTotal scanning API.

The code requests completion of the scanning operation before returning the response.

An API error does not always mean that the file is unknown, so some failed lookups may also lead to an attempted submission.

Interpreting Detection Results

No Known Detections

A report with no detections does not prove that a file is harmless.

New or specialized malware may not be recognized by available scanners.

One or More Detections

Detections should be reviewed in context.

Some detections may be false positives.

Multiple Detections

Multiple independent detections can increase concern, but still require appropriate interpretation.

Analysis Errors

A failed analysis may indicate a provider, authentication, network, or processing problem.

It does not establish whether the file is malicious.

File Privacy

Warning: VerAI may upload submitted files to VirusTotal.

VirusTotal is an external threat-intelligence service, and file submissions may become accessible according to that service's policies and access arrangements.

Do not upload:

• Confidential corporate documents
• Private keys or credentials
• Personally identifiable information
• Sensitive medical or financial documents
• Proprietary source code
• Other files that must remain private

unless submission to the service is explicitly authorized.

Supported File Types

The supplied backend does not restrict the upload to a specific list of file extensions.

The implementation reads file bytes and submits them through the VirusTotal client.

Actual limits and acceptance are subject to application configuration, hosting restrictions, and VirusTotal's API capabilities.

Limitations

VerAI's supplied code does not implement its own malware detection engine.

It relies on VirusTotal for reputation information and external analysis.

The backend also does not provide an independent local sandbox, behavioral malware execution environment, or complete file forensic analysis.

Recommended Workflow

1. Verify where the file originated.
2. Review its filename and expected purpose.
3. Submit it only when external analysis is permitted.
4. Review any returned reputation data.
5. Investigate detections and suspicious metadata.
6. Avoid executing untrusted files solely because no detections were returned.

Important: A clean VirusTotal result does not certify that a file is safe.