""ET TROJAN Win32/Koi Loader CnC Checkin M3""

SID: 2049815

Revision: 1

Class Type: trojan-activity

Metadata: affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Windows_11, attack_target Client_Endpoint, created_at 2023_12_21, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, updated_at 2024_01_02

Reference:

  • md5

  • 09350493580399e2983148e80fd4490b

Protocol: tcp

Source Network: $HOME_NET

Source Port: any

Destination Network: $EXTERNAL_NET

Destination Port: $HTTP_PORTS

Flow: established,to_server

Contents:

  • Value: "POST"

  • Value: "/config.php"

  • Value: "Content-Encoding|3a 20|binary|0d 0a|"

  • Value: "Content-Type|3a 20|application/octet-stream"

  • Value: "Content-Length|3a 20|40|0d 0a|"

  • Value: "102|7c|" Depth: 4

Within:

PCRE: "/102\x7c[a-f0-9]{8}-([a-f0-9]{4}-){3}[a-f0-9]{12}$/P"

Special Options:

  • http_method

  • http_uri

  • http_header

  • http_header

  • http_header

  • http_client_body

  • fast_pattern

source