Now decode the percent-encoded part:
%3A → : %2F → / %2F → / %2F → /
proxy-url-file-%3A%2F%2F%2F
The triple slash suggests the proxy-url-file scheme is (hierarchical with an authority component empty). Conclusion: An Anomaly Worth Investigating proxy-url-file-3A-2F-2F-2F is not a standard, innocent string. It is almost certainly an encoded, hyphenated representation of proxy-url-file:/// — a custom URI scheme with a file-path root. Its presence in logs, configuration files, or network traffic should prompt immediate investigation. Depending on context, it could signal a benign developer mistake, a misconfigured proxy, or a malicious custom protocol handler designed for local file access or code execution. proxy-url-file-3A-2F-2F-2F
Introduction: What You Are Looking At The string proxy-url-file-3A-2F-2F-2F is not a standard protocol, command, or configuration directive. Instead, it is almost certainly a partially URL-encoded or double-encoded string that has been truncated, concatenated, or logged in an unusual way. To the untrained eye, it looks like gibberish. To a systems engineer or security researcher, it reads like a broken version of something familiar: proxy-url-file:/// Now decode the percent-encoded part: %3A → :