1. Download the Official Installer

Version Details

: Version 21.11.2500 (Build 21.11.6809.528) was a legitimate update released by Avast around December 28, 2021 .

How to Check If You Already Installed a Fake Version

Protection:

Even in older iterations, Avast's engine consistently earns high marks from labs like AV-TEST and AV-Comparatives for real-world malware and phishing protection. Report: Avast Premium Security — Version 21

• Produce exact command lines to extract, hash, and scan the RAR in Windows or Linux.
• Provide a checklist tailored for automated sandbox analysis (Cuckoo, Any.Run).
• Analyze a provided hash or file listing (paste the SHA256 or file list) and flag suspicious items.

• Record source URL, download method, and timestamp.
• Compute and store hashes (MD5, SHA1, SHA256) of the RAR and extracted files.
• List all files and sizes from the archive.
• Note any signed binaries and verify signatures.
• Capture process and network traces from sandbox run (process tree, files dropped, registry changes, network endpoints).
• Save AV detection names and engine versions when scanning with multiple scanners.