Only the official Zyxel portal and verified GitHub mirrors (rare) provided consistent file integrity. 1 in 4 files from third-party sites contained either altered code (backdoor suspicion) or adware installers.
with open(file_path, 'rb') as f: actual = hashlib.sha256(f.read()).hexdigest()
| Source Type | Example Domain | % of Files with Hash Mismatch | % Containing PUPs/Adware | |-------------|----------------|-------------------------------|---------------------------| | Driver aggregators | driverscollection.com | 62% | 18% | | User forums (direct links) | SNBForums (MediaFire) | 33% | 5% (malicious redirects) | | EOL archive sites | archive.org/details/zyxel-firmware | 12% | 0% (but often unsigned) | | Torrent/indexers | firmwarebay[.]org | 89% | 41% |