Domain Fronting Detected - SNI vs Host Mismatch
This rule detects potential domain fronting by identifying a mismatch between the Server Name Indication (SNI) field in the TLS handshake and the Host header, specifically when the SNI field contains domains commonly used for content delivery networks (CDNs) like cloudfront.net, azureedge.net, or fastly.net. This technique can be used to obfuscate the true destination of network traffic, often for malicious purposes such as bypassing censorship or exfiltrating data.
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