""ET INFO Suspicious Domain (polyfill .io) in TLS SNI""

SID: 2053893

Revision: 1

Class Type: bad-unknown

Metadata: affected_product Any, attack_target Client_and_Server, created_at 2024_06_26, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, updated_at 2024_06_26

Reference:

Protocol: tcp

Source Network: $HOME_NET

Source Port: any

Destination Network: $EXTERNAL_NET

Destination Port: 443

Flow: established,to_server

Contents:

  • Value: "|16|"

  • Value: "|01|"

  • Value: "|00 00|"

  • Value: "|00|"

  • Value: "polyfill.io"

Within: 1

PCRE: "/^(?:\x00\x0b|.\x2e)polyfill.io/R"

Special Options:

source