""ET TROJAN Cobalt Strike CnC Activity""

SID: 2031806

Revision: 2

Class Type: trojan-activity

Metadata: attack_target Client_Endpoint, created_at 2021_03_03, deployment Perimeter, deployment SSLDecrypt, performance_impact Low, signature_severity Major, updated_at 2021_03_03

Reference:

Protocol: tcp

Source Network: $HOME_NET

Source Port: any

Destination Network: $EXTERNAL_NET

Destination Port: $HTTP_PORTS

Flow: established,to_server

Contents:

  • Value: "GET"

  • Value: "/mt?" Depth: 4

  • Value: "="

  • Value: "lu=" Depth: 3

Within:

PCRE: "/^lu=(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/C"

Special Options:

  • http_method

  • fast_pattern

  • http_uri

  • http_uri

  • http_cookie

source