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

SID: 2033384

Revision: 2

Class Type: trojan-activity

Metadata: attack_target Client_Endpoint, created_at 2021_07_22, deployment Perimeter, malware_family Cobalt_Strike, signature_severity Major, updated_at 2021_07_22, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation

Reference:

  • md5

  • 4ba24c8dd87c35c1d7492eb31a14c2bd

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: "/nova_assets/Sys/_Getcode/keywords=" Depth: 35

  • Value: "skin=" Depth: 5

  • Value: "cfruid="

Within:

PCRE: "/sparrow_init=(?:[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_cookie

  • http_cookie

source