""ET CURRENT_EVENTS Client Cloaking Javascript Observed""

SID: 2033947

Revision: 1

Class Type: trojan-activity

Metadata: affected_product Web_Browsers, attack_target Client_Endpoint, created_at 2021_09_14, deployment Perimeter, performance_impact Low, signature_severity Minor, updated_at 2021_09_14

Reference:

Protocol: tcp

Source Network: $EXTERNAL_NET

Source Port: $HTTP_PORTS

Destination Network: $HOME_NET

Destination Port: any

Flow: established,to_client

Contents:

  • Value: "200"

  • Value: "|3c|html|3e 3c|head|3e 3c|script|20|src|3d 27|"

  • Value: "Aes|2e|Ctr|2e|decrypt|28|"

  • Value: "document|2e|write|28|output|29|"

Within:

PCRE: "/^(?:[^0-9][a-zA-Z0-9_$]{1,254}),\s(?:[^0-9][a-zA-Z0-9_$]{1,254}),\s256)\x3b/Ri"

Special Options:

  • http_stat_code

  • file_data

  • nocase

  • fast_pattern

source