The ZIP format itself is just a container. However, it can be used to hide malicious files from basic email filters.
Below is a blog-style overview of how to handle downloads like this, focusing on identification and safety. Decoding the Download: What is "202113.zip"? Download 202113 zip
Numeric ZIP files are commonly used by developers and automated systems. Possible origins include: The ZIP format itself is just a container
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If a ZIP requires a password provided by a stranger, be wary. Passwords prevent many antivirus scanners from checking the contents. 3. Best Practices for Unknown ZIPs