""ET TROJAN Cobalt Strike Beacon Activity (UNC2447)""

SID: 2032944

Revision: 1

Class Type: trojan-activity

Metadata: attack_target Client_Endpoint, created_at 2021_05_11, deployment Perimeter, deployment SSLDecrypt, signature_severity Major, tag c2, updated_at 2021_05_11, 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"

  • Value: ".htm"

  • Value: "|20 28|compatible|3b 20|"

  • Value: "|3b 20|.NET4.0E|20 29 0d 0a|"

Within:

PCRE: "/^User-Agent\x3a\x20[^\r\n]+\x3b\x20.NET4.0E\x20\x29/Hmi"

Special Options:

  • http_method

  • http_uri

  • fast_pattern

  • http_header

source