""ET TROJAN Ursnif Variant CnC Beacon""

SID: 2021813

Revision: 6

Class Type: trojan-activity

Metadata: attack_target Client_Endpoint, created_at 2015_09_23, deployment Perimeter, performance_impact Significant, signature_severity Major, tag c2, updated_at 2024_04_29, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel

Reference:

  • md5

  • 8ab21ac9199d3ced2230924b90f49f0d

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: "/images/"

  • Value: ".gif"

  • Value: !"Accept"

  • Value: !"Referer|3a|"

  • Value: !"ms-office"

Within:

PCRE: "/^User-Agent\x3a\x20(?:Mozilla\/|Shockwave)/Hmi"

Special Options:

  • http_method

  • http_uri

  • fast_pattern

  • http_uri

  • http_header

  • http_header

  • http_header

source