""ET TROJAN Win32/Bisonal Backdoor CnC Activity (POST)""

SID: 2033964

Revision: 2

Class Type: trojan-activity

Metadata: attack_target Client_Endpoint, created_at 2021_09_16, deployment Perimeter, deployment SSLDecrypt, malware_family Bisonal, signature_severity Major, updated_at 2022_04_18, reviewed_at 2023_08_22

Reference:

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: "/post.asp"

  • Value: ".com#.com|0d 0a|"

  • Value: !"Referer|3a 20|"

Within:

PCRE: "/^Host\x3a\x20[^\r\n]+.com#.com/Hmi"

Special Options:

  • http_method

  • http_uri

  • http_header

  • fast_pattern

  • http_header

source