""ET CURRENT_EVENTS Successful Generic AES Phish M2 Oct 24 2017""

SID: 2024998

Revision: 4

Class Type: trojan-activity

Metadata: affected_product Web_Browsers, attack_target Client_Endpoint, created_at 2017_10_24, deployment Perimeter, signature_severity Critical, tag Phishing, updated_at 2017_11_20, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1566, mitre_technique_name Phishing

Reference:

Protocol: tcp

Source Network: $EXTERNAL_NET

Source Port: $HTTP_PORTS

Destination Network: $HOME_NET

Destination Port: any

Flow: established,from_server

Contents:

  • Value: "Content-Type|3a 20|text/html"

  • Value: "Aes.Ctr.decrypt"

Within:

PCRE: "/^\s?(\s[^,]+,\s?[^,]+,\s?(?:128|256|512)\s*?)/Rsi"

Special Options:

  • http_header

  • file_data

  • nocase

  • fast_pattern

source