""ET TROJAN Cobalt Strike Activity (GET)""

SID: 2034347

Revision: 2

Class Type: trojan-activity

Metadata: attack_target Client_Endpoint, created_at 2021_11_05, deployment Perimeter, signature_severity Major, tag c2, updated_at 2021_11_05, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel

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 /9Wla HTTP/1.1"

  • Value: !"Referer|3a 20|"

Within:

PCRE: "/^Host\x3a\x20\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3}$/Hm"

Special Options:

  • fast_pattern

  • http_header

source